Palestinian officials said Wednesday that they would postpone efforts to arrange a leadership summit with Israel to protest a deadly raid on a Gaza (search) refugee camp, another setback for a long-delayed meeting to reinvigorate stalled peace efforts.

Meanwhile, officials said Israel's government has modified construction of its West Bank security barrier in a move that could lay out its route sooner than previously planned. The decision could bring more international criticism of the contentious project.

In the West Bank, Israeli security forces arrested the son of prominent Palestinian uprising leader Marwan Barghouti (search) as he tried to enter the area from Jordan.

Qassam Barghouti, 19, was being questioned for suspected "terrorist activities," a source in Prime Minister Ariel Sharon's office said on condition of anonymity. Relatives said he was returning from Egypt, where he is a university student.

Early Tuesday, Israel entered the Rafah refugee camp (search) in Gaza to search for weapons-smuggling tunnels.

The troops pulled out a day later, leaving homes and streets damaged and one tunnel destroyed. The raid was marked by heavy fighting between Israeli soldiers and Palestinian militants.

Israeli and Palestinian officials have been trying to arrange a meeting between their prime ministers to restart stalled peace efforts since Palestinian Prime Minister Ahmed Qureia (search) formed a new government in November.

Officials hoped to hold the summit this week. But Qureia aide Hassan Abu Libdeh canceled a preparatory meeting planned Wednesday with Dov Weisglass, the director of Prime Minister Ariel Sharon's office in response to the Rafah incursion, according to Palestinian officials.

"When you have (so many) Palestinians killed in one day it is very difficult to hold a meeting on the same day as the funerals," said Palestinian Cabinet minister Saeb Erekat (search).

Palestinians have said one issue they want addressed in the meeting is the barrier. Its path would cross deep into parts of the West Bank, where Palestinians want to establish an independent state.

Officials close to the project said Israel's government has changed its approach to building the barrier in recent days. Contractors have been ordered to build all structure simultaneously, and not section-by-section as was previously intended, according to senior officials involved in the project.

Although the target date for completion remains 2005, the entire route of the barrier would be at least partially built much sooner, the sources said. So far, about 100 miles of the 450-mile barrier have been completed.

The change is aimed at establishing facts on the ground before the issue is examined at the International Court of Justice in the Hague, said the sources, who spoke on condition of anonymity.

Raanan Gissin, spokesman for Sharon, noted that the prime minister last week promised to speed up construction of the barrier for security reasons. He denied that this was connected to the Hague court, which he says lacks authority over Israel.

"It's irrelevant," Gissin said. "It's not a court that can enforce decisions ... The fence is a reversible means to avert terrorism, but the lives that are lost are irreversible."

Israel says the barrier — a mix of fences, walls and trenches — is intended to the block suicide bombers who have killed hundreds of Israelis in more than 100 attacks over the past three years.

But the project has drawn widespread condemnation for dipping into the West Bank, enclosing major Jewish settlements in what the Palestinians call a major land grab.

Last week Sharon also said he might dismantle some Jewish settlements as part of a unilateral pullout from parts of the West Bank. Some officials say the tactic is aimed at pressuring the Palestinians to return to peace talks.

Israel began construction of the barrier about a year ago and its officials have said the completed sections have already prevented attacks.

In the West Bank city of Nablus, a car exploded near an electronics plant, killing a male who was believed to be a member of the militant group Hamas, Palestinian security sources and witnesses said.

It was unclear what caused the explosion. The Israeli army denied involvement, saying it was not operating in the area at the time. Dozens of Palestinian militants have been killed when bombs they were building or transporting blew up prematurely.