Egyptian mediators have warned Hamas (search) that parliamentary elections set for Jan. 25 could be postponed if the Islamic militants don't abide by a truce, including a promise to keep their weapons at home, an official close to the talks said Thursday.

Palestinian leader Mahmoud Abbas (search) is to meet with Israeli Prime Minister Ariel Sharon (search) next week, ahead of talks with President Bush in Washington on Oct. 20, and is excped to push for an army withdrawal from more West Bank towns. Israel has said it can only move forward if Abbas reins in militants.

Hamas, popular with voters and eager to claim a share of power, wants the election held on time.

Egypt delivered the warning after deadly weekend fighting between Hamas and Palestinian police, said the official, who spoke on condition of anonymity because he is not authorized to talk about the negotiations.

Egypt is increasingly influential in chaotic Gaza, with both the Palestinian Authority (search) and armed groups seeking its backing and good will.

In a statement Thursday, Hamas did not refer to Egypt by name. Hamas alleged it was the target of a conspiracy aimed a "preventing us from participating in political life, either by obstructing the legislative election or by imposing conditions for holding the election."

Over the weekend, three Palestinians, including a policeman, were killed in fighting between Hamas and police. An umbrella group of Palestinian factions has held Hamas responsible for the violence.

As part of an Egyptian-brokered truce in February, the armed groups agreed to stop displaying weapons in public, and the Palestinian Authority has recently begun enforcing the ban. Police in Gaza City have set up roadblocks, checking cars and confiscating weapons.

Israel insists that Hamas not participate in the election as long as it refuses to disarm. In the past two weeks, Israel has rounded up scores of Hamas candidates in the West Bank during a sweep against Palestinian militants.

Abbas is also worried about the growing strength of his main political rival, but it remains unclear whether he would seek to postpone the vote if it becomes apparent Hamas could defeat his corruption-tainted Fatah movement (search). Fatah's prospects could become clearer in December, after municipal elections are held in the largest Palestinian towns and cities.

With an Abbas-Sharon summit looming, the Palestinians want Israel to carry out promises made at a previous meeting in February, including the release of additional Palestinian prisoners and an army withdrawal from more West Bank towns.

Palestinian negotiator Saeb Erekat (search) said the summit is tentatively set for Tuesday, but much depends on a preparatory meeting he'll hold with Dov Weisglass (search), a top Sharon adviser, on Friday. "I don't think Israelis and Palestinians can afford a failed summit at this stage," he said.

The Palestinians hope Israel will show more flexibility in releasing prisoners, including those involved in attacks that killed or wounded Israelis. Nearly 8,000 Palestinians are in Israeli prisons, including 500 rounded up in a new offensive against militants in the past two weeks, in response to rocket fire from Gaza on an Israeli town.

Israeli Vice Premier Ehud Olmert (search) said Thursday that Israel won't consider releasing prisoners involved in attacks, but told Israel Radio that "we can consider anything that can ease the lives of (Palestinians) and won't endanger Israel's security."

Israel's Supreme Court, meanwhile, banned the military's practice of using Palestinian civilians as "human shields" in arrest raids, saying it violates international law.

The ruling was a rare instance in which the court agreed to take a stand in Israel's conflict with the Palestinians.

Human rights groups filed the petition in May 2002, in response to the army's use of Palestinian civilians in dozens of instances during West Bank arrest operations. During arrest raids, soldiers would sometimes force Palestinian civilians to approach the homes and hideouts of wanted people.

In 2002, the court issued a temporary injunction against the practice. Human rights groups have said the military has repeatedly violated the ban since then.

In Thursday's final ruling, the court said the practice amounts to a "slide down the slope toward a severe violation of international law."

The army had argued the practice should be permissible in some cases, to prevent possible shootouts and bloodshed. The Justice Ministry said the state would immediately implement Thursday's decision. An army spokesman would not comment.