Al-Qassam Brigades

Overview

The Al-Qassam Brigades, formally the Izz ad-Din al-Qassam Brigades, are the armed wing of Hamas, a terrorist organization that has ruled the Gaza Strip since violently seizing power there in 2007. Hamas formally established the Brigades in 1991. Their operations have included shootings, suicide bombings, rocket and mortar attacks, tunnel warfare, combat against Israeli forces and hostage-taking. The organization has carried out attacks in Israel and Judea and Samaria as well as operations from Gaza. Its commanders planned and took part in Hamas’s October 7, 2023 invasion and massacre in southern Israel.

The Brigades are Hamas’s principal military formation, but their personnel and activities have not been confined to a single, wholly separate institution. Hamas has assigned members of its Gaza police and internal-security apparatus to Al-Qassam combat missions. Its units have also cooperated with other armed groups. In Gaza, the Al-Quds Brigades of Islamic Jihad were the next-largest armed group during the 2023–2024 war. In Judea and Samaria, Al-Qassam personnel have operated alongside Al-Quds Brigades and Fatah’s Al-Aqsa Martyrs Brigades within the Jenin Battalion umbrella.

Estimates of Al-Qassam’s strength vary. One account placed Hamas’s military wing at approximately 30,000 fighters and another 7,000 reservists, while an analysis of the 2014 Gaza war cautioned that a Hamas estimate of 30,000 Al-Qassam members might be exaggerated. Such figures describe an organization with multiple local formations and specialized units, rather than a small clandestine cell. Its rocket forces, infantry, anti-tank teams, snipers, tunnel networks and naval commandos have given Hamas means to attack Israeli communities and fight Israeli troops.

Founding and ideology

Hamas emerged during the First Intifada from the Muslim Brotherhood. Its military apparatus changed repeatedly as Israeli forces exposed and disrupted cells responsible for attacks. Hamas formally established the Al-Qassam Brigades as its armed branch in 1991; the Izz al-Din al-Qassam Squads carried out attacks under that name from January 1, 1992. The new structure brought Hamas’s organized violence under an identifiable military wing while preserving the wider movement’s political, social and internal-security institutions.

The Brigades adopted Hamas’s Islamist program and its campaign against Israel. Their methods developed from small armed cells into sustained rocket fire, organized ground formations and extensive underground works in Gaza. The distinction between Hamas’s political leadership and its military wing has never meant an absence of coordination. Leaders drawn from, or closely connected to, Al-Qassam have shaped Hamas’s strategy, and the organization’s military decisions have had direct political consequences for the Arabs of Gaza and for Israel.

Saleh al-Arouri helped found Al-Qassam’s organization in Judea and Samaria during the 1990s and later held a senior leadership role. Yahya Sinwar joined the Brigades in 1991 and rose within Hamas while also developing its internal-security apparatus. These careers illustrate how Hamas linked armed operations, security control and political authority from the organization’s early years.

History

Al-Qassam carried out major Hamas attacks beginning in 1992. In December of that year, its members abducted Israeli sergeant Nissim Toledano and demanded the release of Hamas founder Ahmed Yassin. Prime Minister Yitzhak Rabin refused the demand. Al-Qassam operatives carried out their first suicide bombing in 1993. During the Second Intifada, the Brigades became responsible for numerous lethal attacks on civilians. In Amnesty International’s 2002 survey of such attacks, they claimed responsibility for 23.

On March 27, 2002, the Brigades claimed the Passover bombing at a hotel in Netanya. An attacker detonated a bomb in a dining room where guests were celebrating the Jewish holiday, killing 29 people and injuring 140. Twenty-seven of those killed were civilians. Nineteen victims were over 70; the oldest, Chanah Rogan, was 90. On April 27, Al-Qassam claimed an attack on Adora in Judea and Samaria. Gunmen killed five-year-old Danielle Shefi and three adults. A gunman also wounded Danielle’s mother and her brothers, aged four and two. Both attacks exemplified the Brigades’ deliberate violence against Israeli civilians.

After Israel withdrew its forces and Jewish communities from Gaza in 2005, Hamas continued building its armed apparatus there. Hamas violently seized power in Gaza in 2007. From that base, Al-Qassam sustained rocket attacks on Israeli communities and prepared for larger confrontations. During the Gaza War of 2008–2009, known in Israel as Operation Cast Lead, its rockets reached Ashdod, Ofakim, Kiryat Gat and Yavne. The Brigades maintained outposts in Beit Lahiya and Beit Hanoun. Muhammad Yahya Muhanna was among its commanders killed during the fighting; a poster published jointly with Hamas and the Muslim Brotherhood depicted 17 Al-Qassam operatives killed in the operation.

Operation Cast Lead also exposed overlap between Hamas’s Gaza police and its armed wing. Members of Hamas’s internal-security apparatus served as police officers while also carrying out Al-Qassam defensive and offensive missions, both routinely and during emergencies. The dual roles did not disappear when personnel were performing policing duties. Al-Qassam later announced the deaths of two such members in 2009: Ayman Khaled Ibrahim Abu Sibleh, a policeman who died fighting rival jihadis at Rafah’s Ibn Taymiyyah mosque on August 14, and Tariq Farid Abu Jizer, who died during a policing mission in Khan Yunis on August 27. Their cases show how Hamas’s security and military personnel could belong to the same organization.

Al-Qassam members shot and killed four Israelis near Hebron on August 31, 2010. On April 7, 2011, the Brigades struck a school bus near Gaza with an anti-tank missile, killing an Israeli teenager. Rocket fire remained a central part of its campaign. In 2021, the organization displayed the Ayyash 250, which it described as its most powerful rocket, and announced an attempted strike toward Ramon Airport near Eilat. Its arsenal also included other named rocket types with differing ranges.

During the 2014 Gaza War, Al-Qassam combined rocket fire, ground combat, tunnels and naval operations. It reported firing about 3,600 rockets at Israel. Hamas deployed sector-based combat formations with rocket and mortar teams, anti-tank weapons, snipers and infantry. Al-Qassam naval commandos also operated in the war. On October 9, 2014, after the fighting, the Brigades staged a military parade through Gaza as part of a recruitment drive. The organization returned to weapons production and tunnel construction, released a video in August 2015 showing rebuilt tunnels, and held a memorial that month for naval commandos killed in the 2014 war. It also announced that operative Anwar Faraj al-Ghalban died while working on a tunnel east of Khan Yunis in August 2015.

Structure and leadership

Mohammed Deif commanded the Al-Qassam Brigades for years, with Marwan Issa serving as his deputy. Deif directed the military wing in Gaza and coordinated with Yahya Sinwar, Hamas’s leader there, in planning the October 7, 2023 attacks. Sinwar’s rise through Hamas connected the Brigades with its internal-security and civilian governing structures. He sought to maintain civilian stability in Gaza while preserving Hamas rule and expanding its military capacity. Mohammed Sinwar was also a member of Al-Qassam.

The organization’s brigades and smaller formations were assigned geographic and operational roles. Its Rafah Brigade was one of the southern Gaza units that took part in the October 7 invasion alongside other Hamas forces. Al-Qassam’s own publications identified Mohammad Sami Jarghoun as a Rafah Brigade member and Mohammed Manhal Abu Armana as a platoon commander. Those military identifications matter when a person is also described publicly by a civilian occupation: Al-Qassam membership and a civilian job are not mutually exclusive. During the 2014 Gaza war, the organization’s sector formations included infantry, rocket and mortar crews, anti-tank teams and snipers, supported by tunnels and specialized naval personnel.

Hamas’s security services supplied personnel for Al-Qassam operations. The overlap was visible during Operation Cast Lead, when police and other internal-security members were integrated into combat assignments. It was also reflected in the Brigades’ announcements about personnel killed while performing policing missions. Hamas thus used its governing institutions in Gaza as part of a wider system of armed control. In Judea and Samaria, its Al-Qassam network developed through figures including Saleh al-Arouri and cooperated at times with other armed organizations.

Israel killed Deif in an airstrike near Khan Yunis on July 13, 2024. The Brigades later memorialized him as their deceased chief of staff in a July 2025 post. Izz al-Din al-Haddad took command after Deif’s death. The strike that killed al-Arouri also killed Al-Qassam commanders Azzam al-Aqra and Samir Fendi, another loss within the organization’s senior ranks during the war that followed October 7.

Funding and sponsors

The regime in Iran has supplied Hamas’s military wing with money, equipment and expertise. After the 2014 Gaza war, that support helped Hamas rebuild attack tunnels and replenish rockets. In 2015, Qasem Soleimani, commander of the Islamic Revolutionary Guard Corps’ Quds Force, directly ordered millions of dollars sent to Al-Qassam for tunnel reconstruction. Sinwar later credited Iranian-regime funds, equipment and expertise with improving Hamas’s military capability during Soleimani’s command. The sponsorship connected Al-Qassam’s rebuilding program to Iran’s wider network of armed partners.

Al-Qassam also sought smaller contributions through digital payment channels. In early 2019, it asked supporters to send Bitcoin and publicized wallet addresses. Within less than a week, those wallets had received more than $2,500 in Bitcoin. The appeal followed financial pressure on Hamas and showed the Brigades trying to raise funds directly from sympathizers outside conventional banking channels. The publicly observed transfers were small beside the Iranian-regime support used for weapons and tunnels, but they revealed another method of financing the organization.

Money and material support translated into military capacity. Tunnel rebuilding restored routes for movement, concealment and attacks; replenished rocket stocks enabled further fire into Israel. The Brigades’ public tunnel video in 2015 and its continuing rocket development demonstrated those priorities after the 2014 war. Its ability to maintain armed formations while Hamas governed Gaza also rested on access to personnel, facilities and security structures under Hamas control.

Attacks and operations

The Brigades’ record includes direct attacks on civilians, indiscriminate rocket fire, assaults on Israeli forces and hostage-taking. The Netanya Passover bombing and the Adora killings were among the best-known attacks of the Second Intifada. Later operations included the 2010 shooting near Hebron and the 2011 anti-tank missile strike on a school bus. From Gaza, Al-Qassam fired rockets toward Israeli cities during Operation Cast Lead and reported thousands more launches during the 2014 war. Its ground forces fought through infantry, anti-tank, sniper and mortar units, while tunnels offered protected routes and positions.

On October 7, 2023, Al-Qassam participated in Hamas’s coordinated invasion of southern Israel and massacre of civilians. The assault killed more than 1,200 people and seized roughly 250 hostages. Deif coordinated its planning with Yahya Sinwar, and the Rafah Brigade took part alongside other Hamas units. Attackers entered Israeli communities and other civilian sites, killed residents and visitors, and abducted people into Gaza. The scale of the killings and hostage-taking made the operation a turning point in the organization’s history and led to the Gaza war that began in 2023.

Al-Qassam held Israeli hostages in underground tunnel networks in Rafah and elsewhere in southern Gaza during the ensuing war. Detention underground tied the hostage crisis to the tunnel system that Hamas had built and rebuilt over many years. During a November 2023 hostage release in Gaza, Al-Qassam members appeared together with Al-Quds Brigades members before crowds, reflecting cooperation between the two armed organizations. Hostage-taking remained a central feature of Hamas’s conduct of the war, alongside combat with Israeli forces and continued use of Gaza’s underground infrastructure.

The Brigades also used public displays to promote their operations and personnel. Their parades, memorial videos, obituaries and battlefield announcements served recruitment and propaganda purposes while sometimes identifying members’ military roles. In 2024, some anti-Israel protesters in New York displayed images of Deif alongside Sinwar and Al-Qassam spokesman Abu Obaida. Other demonstrations featured praise for the Brigades. Such displays showed the organization’s symbols and leaders being celebrated beyond Gaza even as its October 7 attack and hostage-taking remained central to the war.

Designations and international status

Hamas is a terrorist organization, and Al-Qassam is its armed wing. The United States designated Hamas a Foreign Terrorist Organization in 1997 and has described the Brigades as its military element. An Egyptian court designated the Al-Qassam Brigades a terrorist organization in February 2015. Australia has listed the Brigades under its counterterrorism law. These measures address an organization responsible for deliberate attacks on civilians, rocket fire toward populated areas and hostage-taking.

Debate over whether Hamas’s political and armed branches can be treated as separate institutions has practical consequences for sanctions and counterterrorism policy. The Brigades have an identifiable command structure and combat units, but senior Hamas leaders have helped establish, direct or coordinate their operations. Hamas’s Gaza police and internal-security personnel have also served in Al-Qassam. Those links make the Brigades integral to Hamas’s exercise of power, rather than an independent force operating outside it.

Current status

Israel’s killing of Deif in 2024 and other senior commanders damaged Al-Qassam’s leadership during the war begun by the October 7 attack. Izz al-Din al-Haddad succeeded Deif in command. The organization continued to be identified with Hamas’s armed forces in Gaza, its tunnel network and the detention of Israeli hostages during the ensuing conflict. Deif’s later memorialization as chief of staff underscored his place in its institutional history after his death.

The Brigades’ development from 1991 cells to organized Gaza formations links several decades of Hamas violence. Their history encompasses the abduction of Nissim Toledano, mass-casualty attacks during the Second Intifada, rocket campaigns and tunnel warfare in successive Gaza wars, and the October 7, 2023 invasion and hostage crisis. Iranian-regime sponsorship, integration with Hamas’s governing and security apparatus, and cooperation with other armed groups have helped sustain that capacity. Their attacks on civilians and role in Hamas’s wars remain defining features of the organization.