A Palestinian former professor is on trial in the United States charged with providing financial and other backing for the Palestinian militant group Islamic Jihad.

The group is on a U.S. list classifying it as a terrorist organisation.

Defendant Sami al-Arian and three co-defendants have denied the charges and said they were being prosecuted only because of their political support for the Palestinians against Israel.

Here are five facts about Islamic Jihad:

* Islamic Jihad is sworn to destroying Israel and replacing it with an Islamic state spanning what was pre-1948 British Mandate Palestine, including the West Bank and Gaza, which Israel captured in the 1967 Middle East war.

* The group was founded in the 1970s by Fathhi Shiqaqi, who was assassinated in 1995 by Israeli security agents. It began attacks in Israeli-occupied Gaza in the early 1980s with a series of stabbings of Israelis and shootings at army bases.

* Islamic Jihad, along with militants from larger Islamist faction Hamas, began a suicide bombing campaign against Israelis in 1994 after a far-right Jew massacred 29 Palestinians in a Hebron mosque. A few months before, the mainstream Palestinian Fatah leadership had reached an interim peace deal with Israel.

* Islamic Jihad, along with Hamas and Fatah militants, in 2000 launched a revolt including a wave of suicide attacks in Israel, before adopting a de facto ceasefire in February 2005 at the behest of new moderate Palestinian President Mahmoud Abbas.

* The group has been involved in scattered attacks that broke the truce, including a Feb. 25 suicide bombing that killed five Israelis, and a mortar barrage against Jewish settlements in Gaza on June 7 that killed three non-Israeli labourers, including two Palestinians. Islamic Jihad said it was only avenging Israeli raids that killed or captured comrades.

* Unlike Hamas, Islamic Jihad has limited popular appeal and does not intend to run candidates in an upcoming parliamentary election. Islamic Jihad denies Israeli charges that it has been funded by the Iranian-backed Hizbollah group in Lebanon.