Palestinian leaders expressed concern in recent interviews that Israel's plan for a phased withdrawal from the Gaza Strip risks increased violence, and called on Israeli leaders to negotiate the terms of the pullout, rather than depart unilaterally.

If the Palestinian Authority is expected to halt violence in Gaza, it needs to be able to offer a clear political program, said Mohammed Dahlan, the former security chief in Gaza who continues to wield power here without official position. "There's no other idea except the withdrawal from Gaza on the table, no political ideas or political plan," Dahlan said.

Fighting by militant groups, against Israel or even against other Palestinian factions, could best be suppressed "if there is serious negotiation and serious hope for the future," Dahlan said.

"If the Palestinian side is not a real partner in this plan, there will not be quiet during the phases of the withdrawal," said Samir Masharwi, the general inspector of the Palestinian interior ministry in Gaza.

Representatives of Palestinian militant groups, security chiefs and politicians in Gaza said in interviews that Israeli Prime Minister Ariel Sharon's proposed pullout of Israeli soldiers and settlers does not offer a clear political outcome that would give militants an incentive to stop attacks.

Israeli officials have said they are considering a unilateral pullout because there is not a Palestinian partner to negotiate with, and they have often accused the Palestinian Authority of failure to halt terrorist attacks on Israeli targets.

"I don't think that any partial withdrawal will help the situation," said Marwan Kanafani, a Gaza representative to the Palestinian Legislative Council who has been involved in talks between factions on cooperation after an Israeli withdrawal. "I think, on the contrary, it might ignite it more," he said.

The proposed Israeli handover would be "gradual, based on performance," said Ziad Abu Amr, a Gaza representative on the Palestinian Legislative Council, "which leaves any initial arrangement susceptible to intervening circumstances."

Continuing Israeli military strikes have added to Palestinian doubts that a withdrawal could proceed peacefully. On Saturday Israeli forces demolished another 20 houses in Rafah and fired two rockets in Gaza City, killing a civilian and two militants from the Islamic Resistance Movement, or Hamas.

Representatives of militant groups said they had no consensus about how to react to a withdrawal.

A spokesman for Hamas said the group would stop launching attacks from Gaza if Israeli forces and settlers were entirely withdrawn. "But that's not what we're looking at now," said Sami Abu Zohri.

Abu Qusay, of the Rafah division of al-Aqsa Martyrs Brigades, which is linked to Yasser Arafat's Fatah organization, said in an interview that his organization would lay down arms if the Palestinian Authority reached an agreement with militant groups. But he made his own demand: "We need the prisoners from Israeli jails and the remains of bodies."

Smaller groups, too, laid out separate conditions for a cease-fire. There must be guarantees for Palestinian statehood, said Sami Abu Samhadaneh, who is affiliated with the Popular Resistance Committees, made up of defectors from Fatah, Hamas and Islamic Jihad.

The Palestinian Authority has been discussing power-sharing with militant groups in Gaza for several years. Recently, that dialogue has focused on the aftermath of an Israeli withdrawal, according to participants in the meetings.

Weeks before the assassination by Israel of Sheik Ahmed Yassin, the Hamas leader had announced a plan for Hamas, Fatah and other factions to unite in administering Gaza in the event of a unilateral withdrawal. But negotiations were stalled by his death and the assassination of his successor, Abdel Aziz Rantisi, said Palestinian Authority members who had been part of the talks. The new Hamas leadership has avoided such meetings for fear of assassination.

"There is no evidence of a major serious effort taking place on the ground," said Abu Amr, who had been part of the talks among factions and has published books about Hamas. "Political decisions are lacking."

The Palestinian Authority, uncertain about Israel's intentions, is unprepared politically for an Israeli withdrawal, Abu Amr and Kanafani said.

Palestinian leaders said they are also concerned about restructuring their own security forces. Egypt plans to send a delegation in June to consult about restructuring the forces, Masharwi said. But leaders said that Palestinians must find a way to assimilate militants into a stable structure for governing Gaza.

Gaza leaders also expressed dismay that the current Israeli plan would allow continued Israeli control of ports and borders, which they said would strangle economic activity and prevent passage of people across the border with Egypt.

"Some people have optimistic points of view on this volatile area of shifting sands," said Abu Amr, the Palestinian legislator. "I don't know what's going to happen tonight. This place is so fragile, any event can create new realities."

A political plan, not simply a withdrawal, is needed to reduce Gaza violence, says Mohammed Dahlan, the former Palestinian security chief in Gaza."I don't think that any partial withdrawal will help the situation," said Marwan Kanafani, a Gaza representative to the Palestinian Legislative Council.