AIN EL-HELWEH, Lebanon (AFP) -– The Fatah party of Palestinian president Mahmud Abbas staged a show of force on Sunday in the largest of Lebanon's 12 refugee camps, the scene of recent clashes with Islamists.

The parade at Ain el-Helweh on the outskirts of the southern port city of Sidon also marked the fourth anniversary of the death of veteran Palestinian leader Yasser Arafat.
Nearly 400 Fatah fighters toting automatic weapons and rocket-propelled grenade launchers marched down a main road in the camp watched by a large crowd, an AFP journalist said.
Two vehicles mounted with anti-aircraft guns were also paraded inside the camp for the first time since the end of Lebanon's 1975-1990 civil war.
On Thursday a Fatah member was shot dead by an unidentified gunman in Ain el-Helweh. In recent months the camp has seen several clashes between Fatah and a mainly Sunni outlawed group, Jund al-Sham (Soldiers of Damascus).
The Palestinian refugee camps in Lebanon are considered highly volatile and fertile breeding grounds for extremists.
In 2007 more than 400 people, including 168 soldiers, were killed in a 15-week battle in the northern Nahr al-Bared camp before the Lebanese army defeated Islamists holed up there.
Extremists believed to have links with Al-Qaeda have settled in the country's Palestinian refugee camps, especially in Ain el-Helweh.
Munir Makdah, commander of a force which polices the camp, said later that a Jund al-Sham militant, Mohammed al-Dukhi, also known as Abu al-Jarrah, was arrested on Sunday inside Ain el-Helweh and handed over to the Lebanese army.
The army does not enter the camps, leaving responsibility for security to Palestinian factions.