In a pitched gun battle in Gaza on Tuesday night at least 21 members of rival Arab militias were killed. Prime Minister Ehud Olmert said that Israel was not going to get involved in the Palestinian Authority's civil war, which he described as being "between pragmatic and extremist Palestinian forces."

PA sources said that 11 of the dead from the most recent clash were members of the Islamist Hamas terror organization, while the other 10 belonged to PA Chairman Mahmoud Abbas's veteran Fatah terror organization. The battle broke out in Jabaliya Tuesday night as armed Hamas and Fatah members vied for control of a local building belonging to an official PA militia.

With the latest carnage in Jabaliya, the number of fatalities in the last 36 hours of PA internecine fighting rose to at least 43. Senior terrorists in both Hamas and Fatah said Tuesday that their loyalists are prepared for an all-out war for control of the PA.

PA Chairman Abbas (Abu Mazen) characterized the series of violent clashes between Hamas and his own Fatah militias as "an attempted coup." The Fatah-run Al-Aksa Martyrs Brigades went on high alert, with the leadership calling on all members to go out into the Gaza streets armed and prepared to challenge gunmen from the Hamas.

Prime Minister Ehud Olmert said Tuesday, "The situation in Gaza is worrisome and problematic insofar as the ability of the pragmatic forces in the Palestinian Authority to withstand the activities of the extremist forces." He made the comments during a meeting with Dutch Foreign Minister Maxime Verhagen. Olmert went on to explain that he sees the potential fall of Gaza into the hands of Hamas as an event with regional repercussions.

"Israel defends itself and will defend itself and its citizenry from any aggression by terrorist organizations, as it deems necessary. We cannot enter the Gaza Strip in order to fight the battle of the Palestinian pragmatic forces against the extremist forces," the Prime Minister added.

Earlier today, the "pragmatic forces" of Fatah, as Olmert called them, issued a threat to exterminate the entire Hamas membership in Judea and Samaria. A spokesman for the Fatah's Al-Aksa Martyrs Brigades, Abu Udai, declared to the Bethlehem-based Ma'an news agency, "If the Hamas movement continues to assassinate Fatah activists in the Gaza Strip - as it killed the northern Gaza Al-Aksa Martyrs Brigades commander Jamal Abu Al-Jidian and his family - then we will wipe out the entire leadership and all the activists of Hamas in the West Bank."