[37][42][43][44][45][46] Led by Mohammed Deif until his death on 13 July 2024, the Al-Qassam Brigades is the largest and best-equipped militia operating within the Gaza Strip in recent years.

[64] Before dying in a shootout with the Palestine Police Force in 1935, al-Qassam exhorted his followers to embrace martyrdom and fight until the last bullet, which turned him into a role model for Palestinian nationalists.

[68] During the Second Intifada, the leaders of the group were targeted by numerous airstrikes that killed many members, including Salah Shehade and Adnan al-Ghoul.

[47][71] In 1986, Shehada formed a network of resistance cells, called al-Mujahidun al-Filastiniun ('Palestinian fighters'), who targeted Israeli troops and "traitors."

[77] The EQB's transition to a recognised militant organisation began during the establishment of the Oslo Accords to assist Hamas efforts in blocking them.

In June 2008, Egypt brokered a ceasefire, which lasted until 4 November when Israeli forces crossed into Gaza and killed six Hamas fighters.

[101][102] Al-Qassam spokesman Abu Obaida stated in a public speech in 2023 during the Gaza–Israel conflict that 85% of their recruits are orphans desiring revenge whose parents were killed by the Israeli Defense Forces.

[106] Although the Brigades manufacture their own weapons,[107] an Associated Press analysis found that the majority of their arms come from China, Iran, and Russia, as well as North Korea and former Warsaw Pact countries.

[111] The Brigades have a substantial inventory of light automatic weapons and grenades, improvised rockets, mortars, bombs, suicide belts, and explosives.

[113][better source needed] Additionally, the Brigades have an estimated 30,000 operatives "of varying degrees of skill and professionalism" who are members of the internal security forces, Hamas, and their supporters.

[116] According to a statement by CIA director George Tenet in 2000, possibly referring to the Brigades, Hamas has pursued a capability to conduct attacks with toxic chemicals.

In one case, nails and bolts packed into explosives detonated by a Hamas suicide bomber in a December 2001 attack in Ben-Yehuda Street in Jerusalem were soaked in rat poison.

Each regional brigade had a number of strongholds and outposts, and included specialised arrays for rocket firing, anti-tank missiles, air defenses, snipers, and engineering.

[118] On 3 September 2005, after Israel's withdrawal from settlements in the Gaza Strip, the Al-Qassam Brigades revealed for the first time the names and functions of its commanders on its website as well as in a printed bulletin distributed to Palestinians.

[137] On 12 July 2006, the Israeli Air Force bombed a house in the Sheikh Radwan neighborhood of Gaza City, where Mohammed Deif, Ahmad al-Ghandur, and Raid Said were meeting.

[138] On 1 January 2009, Nizar Rayan, a top Hamas leader who served as a liaison between the Palestinian organization's political leadership and its military wing, was killed in an Israeli Air Force strike during Operation Cast Lead.

[141][142][143][144] On 3 January 2009, Israeli aircraft attacked the car in which Abu Zakaria al-Jamal, a leader of Izz ad-Din al-Qassam armed wing, was traveling.

According to Israeli authorities Hamdan was in charge of rocket attacks against Beersheba and Ofakim, while Hilo was reportedly behind Hamas' special forces in Khan Yunis.

[146] On 15 January 2009, the Israeli Air Force bombed a house in Jabaliya, killing a prominent Brigades commander named Mohammed Watfa.

[147] On 30 July 2010, one of the leaders Issa Abdul-Hadi Al-Batran, aged 40, was killed at the Nuseirat refugee camp in the central Gaza Strip by an Israeli airstrike.

[148] On 14 November 2012, Ahmed Jaabari, the head of the Al-Qassam Brigade, was killed along with seven others in Gaza, marking the beginning of Israel's "Operation Pillar of Defense".

[43][149] On 21 August 2014, an Israeli air strike killed Muhammad Abu Shamala, the sub-commander of Southern Gaza Strip; Raed al Atar, the commander of the Rafah company and member of the Hamas high military council; and Mohammed Barhoum.

[152] Marwan Issa, deputy leader of the Al-Qassam Brigades and second-in-command to Mohammed Deif, was reported to have been killed by Israeli forces on 10 March 2024.

[77] The Al-Qassam Brigades are explicitly listed as a terrorist organization by the European Union,[52] Australia,[53] New Zealand,[54] Egypt,[55] and the United Kingdom.

[62][63] After Israel launched the ground invasion of Gaza on 27 October, the Qassam Brigades publicised many of their ambushes against Israeli vehicles on their military media for the battle of al-Aqsa Flood.