Hamas's military branch, the Izz ad-Din al-Qassam Brigades, was created in 1991. Although the Brigades are an integral part of Hamas, they operate independently, and at times contrary to Hamas policy. During the 1990s the al-Qassam Brigades conducted numerous attacks against civilians and the Israeli military. From April 1993 these included suicide bombings, for which Hamas became well-known internationally. A major motivation for Hamas’s decision to use suicide attacks as its primary modus operandi was the February 1994 massacre by Baruch Goldstein of 30 Muslims in a Hebron mosque. The Brigades’ Yahya Ayash who may have masterminded most of the early suicide attacks, was killed by the Israeli secret service in early 1996.
In December 1992 Israel responded to the killing of a border police officer by deporting 415 leading figures of Hamas and Islamic Jihad to Lebanon, which provoked international condemnation and a unanimous UN Security Council resolution condemning the action.
Although the suicide attacks by the al-Qassam Brigades and other groups violated the 1993 Oslo accords (which Hamas opposed), Palestinian Authority President Yasir Arafat was reluctant to pursue the attackers and may have had inadequate means to do so. Some analysts stated that the Palestinian Authority could stop the suicide and other attacks on civilians but refused to do so.
In September 1997, Israeli agents in Jordan attempted but failed to kill Hamas leader Khaled Mashaal, leading to chilled relations between the two countries and release of Yassin, Hamas’s spiritual leader, from Israeli prison. Two years later Hamas was banned in Jordan, reportedly in part at the request of the United States, Israel, and the Palestinian Authority. Jordan's King Abdullah feared the activities of Hamas and its Jordanian allies would jeopardize peace negotiations with Israel, and accused Hamas of engaging in illegitimate activities within Jordan. In mid-September 1999, authorities arrested Hamas leaders Khaled Mashaal and Ibrahim Ghosheh on their return from a visit to Iran, and charged them with being members of an illegal organization, storing weapons, conducting military exercises, and using Jordan as a training base. Hamas leaders denied the charges. Mashaal was exiled and eventually settled in Syria.
Read more about this topic: History Of Hamas