Palestinian Authority President Mahmoud Abbas accepted the resignation of a top security chief Saturday and ordered hundreds of senior security officers to retire in a bid to reform his forces and halt violence, an official said.

Abbas, who took office Jan. 15 after the death last year of longtime Palestinian leader Yasser Arafat, has been under pressure from Israel and Washington to impose law and order in the West Bank and Gaza Strip.

Israel and the United States have demanded that the Palestinians streamline their corruption-plagued security forces, which under Arafat ballooned into nearly a dozen branches with often overlapping authorities and rivalries. The Palestinian Authority has 45,000 to 50,000 security officers on its payroll.

"We will not allow anyone to take the law into his own hands and sabotage our situation," Abbas said, criticizing the security services.

"I want to distinguish between nationalists and criminals," Abbas said in remarks broadcast on Palestinian television. "The security apparatus did not perform its duty, so it was crucial to take a stand," he added, in his most blunt criticism yet of the forces...

Palestinian Authority Chairman Mahmoud Abbas's decision to fire Haj Ismail Jaber, commander of the National Security Forces in the West Bank, has done little to allay the fears of this city's residents.

Jaber, a longtime ally of Yasser Arafat, was sacked after he refused carry out Abbas's order to arrest the Fatah gunmen who rioted in the city last week, shooting at the Mukata compound and damaging several restaurants and shops. During a meeting with Abbas, Jaber warned that were he to have intervened, this would have triggered street battles between his men and the gunmen, with many casualties.

Both Abbas and the ousted security chief are aware that the use of drastic measures against the gunmen, most of whom are wanted by Israel, would play into the hands of their rivals, who would depict them as "collaborators." ...

Palestinian militants fired either a mortar shell or a Qassam rocket before dawn Saturday, which hit a barracks housing Palestinian security officers, Israel Radio reported.

The militants launched the explosive from the northern Gaza Strip town of Beit Lahiya, according to Israel Radio...

According to a senior Israel Defense Forces officer, "the transfer of security control in Jericho and Tulkarm has not led to the dismantling of the terrorist infrastructure."

"The cities became 'cities of refuge' for terrorists who do whatever they want," he said.

"The way things look, we're not moving in the direction of transferring security control of Kalkilya until the Palestinians show us proof of changes in the field, dismantling the terrorist infrastructure, unifying the security forces, and collecting weapons."

According to the officer, the reason for the reduction in attacks in recent days is not due to PA efforts but rather to a strategic decision by the terrorist organizations to temporarily cease their actions against Israel.

"They are focused totally on regaining strength," he said.

"When we tell the Palestinians about warnings of impending attacks by terrorist organizations, instead of dealing with it, they run to tell the terrorists that the IDF is looking for them....The great fear is that this will blow up in our faces."

According to the officer, last week there were eight attempts to smuggle weapons from Egypt to Gaza and in only two cases were the smugglers caught.