FACTBOX: Facts about militant group Fatah al-Islam

(Reuters) - Lebanese troops fought militants from the Fatah al-Islam group around a Palestinian refugee camp on Monday, a day after 57 people were killed in battles there and in the nearby northern city of Tripoli, security sources said.

Here are some facts about Fatah al-Islam:

- The faction emerged in November when it split from Fatah al-Intifada (Fatah Uprising), a Syrian-backed Palestinian group. Fatah al-Islam had some 200 fighters at the time, based in Nahr al-Bared camp. Security sources have said militants from other Palestinian camps have joined the group since then and have been trained at the camp.

- The Lebanese government links Fatah al-Islam to Syrian intelligence. Syria and Fatah al-Islam deny any links to each other. The government says four Syrian members of Fatah al-Islam confessed to bombing two buses in February in a Christian area near Beirut. Three people were killed in the attacks.

- Fatah al-Islam's leader, Shaker al-Abssi, is a veteran Palestinian guerrilla. He was sentenced to death in Jordan for killing a U.S. diplomat in 2002. The slain leader of al Qaeda in Iraq, Abu Musab al-Zarqawi, received a similar sentence for the same crime.

- Abssi says his group has no organizational links to al Qaeda but agrees with its aim of fighting infidels. Fatah al-Islam statements have appeared on Islamist Web sites known to publish al Qaeda statements.

- Abssi told Reuters in March that his group's main mission was to reform the Palestinian refugee community in Lebanon according to Islamic sharia law before confronting Israel.