The “military wing” of Hamas, used as the movement’s apparatus for carrying out terror attacks. It is named after Sheikh al-Qassam, considered by Hamas to be the founder of the modern Palestinian resistance movement, killed by the British in 1935. This apparatus became prominent due to its widespread execution of suicide attacks and mass killings, beginning in 1993. The suicide terror attacks climaxed during the early years of the Second Intifada (which began in September 2000). In these attacks, which were carried out mainly in buses and in crowded entertainment areas, hundreds were killed, and thousands were wounded. Counter-terror activity undertaken by Israel (beginning with Operation Defensive Shield, March 2002), and the establishment of the buffer zone in Samaria, led to a significant decrease in Hamas’s success in carrying out suicide attacks in Israel. Alongside the suicide attacks, this apparatus also carried out attacks involving kidnappings of Israelis, explosives attacks, and shooting attacks from passing vehicles. In the past decade, the apparatus has focused on developing its ability to carry out high-trajectory fire from the Gaza Strip (locally produced mortars, and rockets of the “Qassam” type) as well as on improving high-trajectory weapon range and exactitude; and, since the Israeli disengagement from the Gaza Strip (September 2005), on weapon smuggling as well.