A top Palestinian official said Monday that Palestinian police will do all they can to free an Israeli taxi driver feared kidnapped by militants, and Palestinian prisoners in Israel called for the missing man's release.

The disappearance of 61-year-old Eliyahu Goral has stoked Israeli fears that a unilateral truce by the Palestinians could break down because of rogue operations by Palestinian groups, forcing Israeli retaliation. The June 29 truce declaration has brought two weeks of relative calm.

In London, Israeli Prime Minister Ariel Sharon (searchwas rebuffed by Britain in his calls to boycott longtime Palestinian leader Yasser Arafat (search), whom Israel and the United States accuse of fomenting terrorism.

"We will continue to have dealings with (Arafat) as long as we judge it to be useful," a British official said after Sharon met with British Foreign Secretary Jack Straw (search).

Meanwhile, Prime Minister Mahmoud Abbas (searchmet with Arafat to settle their differences, according to senior Palestinian officials.

Legislator Saeb Erekat said the final say over contacts with Israel would remain with the PLO, headed by Arafat, emphasizing that Abbas is not a free agent in his dealings with Sharon.

Arafat reluctantly appointed Abbas under intense international pressure in April.

"Unfortunately there are some violations of the truce, and we will deal with them in accordance with the law," Abbas said after the talk with Arafat.

In the latest violence, a Palestinian man with a knife stabbed three people early Tuesday in Tel Aviv before he was wounded and captured, police said, calling it a terror attack.

The man stabbed a security guard in the neck as he tried to enter a seaside restaurant in south Tel Aviv around 2 a.m. He fled with the guard and the restaurant's owner in pursuit, stabbing two more people before the guard stopped him by shooting him in the legs.

Renegade groups of Palestinian militants have rejected the truce and continue to attack Israelis. However, a Palestinian official who met with their leaders said Monday they pledged to stop their attacks if Israel withdraws from Jenin and Nablus in the northern West Bank. Israeli officials were not available for comment.

In the search for the missing driver, Israel imposed a curfew on the West Bank town of Ramallah. Goral's cab was found abandoned and idling in an Arab section of Jerusalem on Friday.

Palestinian leaders took pains to show they are cooperating with Israel to solve his disappearance.

"President Arafat has instructed all Palestinian security forces to search for this driver and to get him and to give him back if he is in our areas," Erekat said.

Prisoner representative committees at the Ashkelon and Shatah prisons also released a statement calling for Goral's freedom.

Although no group has claimed responsibility for kidnapping Goral, Israeli officials fear he was abducted by militants looking for a prisoner swap.

Palestinians are insisting that Israel release the estimated 7,000 Palestinian prisoners it holds, most accused of terrorist acts. Israel has agreed to free only several hundred and says that prisoners involved in the killing of Israelis cannot be released.

Although it would be unusual for militants to kidnap an Israeli and not take responsibility for the action, it would not be without precedent.

In 1989, two Israeli soldiers were kidnapped in southern Israel; the body of one was discovered three months later, the remains of the second seven years later.

The U.S-backed "road map" for ending 33 months of violence does not speak of a release of prisoners, but Israel has said it would release prisoners to as a gesture to Abbas, who is backed by the United States as an alternative to Arafat as a peacemaker.

Despite some hopeful signs, the road map plan envisaging a Palestinian state by 2005 has been mired in disagreements. Israel is demanding a disarmament of militant groups, as called for in the road map.

But the Palestinian Authority (searchfears forcing militants to give up their weapons could spark civil war. A top leader of the Hamas group warned Monday that attempts to disarm it would bring a return to attacks on Israelis.

"This is just a warning message to the Palestinian Authority that disarming the Palestinian fighters will lead to the end of the initiative declared," said Abdel Aziz Rantisi.

Israel, which pulled out of parts of Gaza and the West Bank town of Bethlehem after the truce, says there will be no further withdrawals from the West Bank towns it holds until a Palestinian crackdown on the militants has begun.

Hamas (search), along with Islamic Jihad (search), is responsible for the majority of homicide bombings against Israel.