The city is shaking

Hebron resident

Witnesses said Israeli tanks shelled Palestinian buildings, setting one on fire.

It is the heaviest outbreak of fighting in Hebron since a US-sponsored truce took effect a month ago.

An Israeli army spokesman said a Palestinian was shot dead by Israeli troops in a separate incident in the Gaza Strip on Friday.

The spokesman said he was preparing to throw a grenade.

A Jewish settler walks by burning debris in Hebron

The latest violence follows an appeal to Israel from the outgoing US ambassador, Martin Indyk, not to give up on peace with the Palestinians.

Israeli troops briefly entered the Palestinian-controlled part of Hebron and destroyed three police posts, Palestinian security officials said.

Two police and 21 other Palestinians were wounded, they said. Hebron was blacked out by an electric power cut.

"The city is shaking, " a witness told Reuters news agency.

Israeli Prime Minister Ariel Sharon, on a visit to Rome, warned that Israel's military response would escalate at the pace of the Palestinian attacks.

Police posts shelled

After meeting Italian leaders, he said his security cabinet had approved a number of steps. "I estimate that a certain amount of time will pass and we will carry them out," he said.

Prime Minister Sharon meets Italian Foreign Minister Ruggiero

On Thursday, Palestinians opened fire at an Israeli vehicle near Nablus, wounding three, including a baby. An Israeli was critically wounded in another road ambush near Hebron.

A faction of Palestinian leader Yasser Arafat's Fatah movement took responsibility for the attack near Nablus and released a videotape of the incident, showing the Israeli car turning in the middle of the road to flee the gunfire, which apparently came from another car.

In response Israeli tanks fired shells at two Palestinian police posts in Nablus, killing a Palestinian intelligence officer.

Angry settlers smashed Palestinian property and burned West Bank fields.

At a meeting on Thursday the Palestinian Cabinet charged Israel with aggression and said that the Palestinians were fully committed to the cease-fire plan worked out last month by CIA director George Tenet.

Radicals

Speaking at Tel Aviv University a day before his planned departure, Mr Indyk said Mr Arafat was not doing enough to stop violence.

But he urged his audience not to listen to Israeli calls for Mr Arafat's overthrow, warning that he would be replaced by radicals from the militant Islamic Hamas or the Iran-backed Hezbollah.

"It is possible to get him to stop the violence," Mr Indyk said.

Israeli fire earlier destroyed a Palestinian police post

"It requires a combination of Israeli restraint, international pressure led by the United States, the threat of terrible consequences if he doesn't and the promise of a credible political process to redress Palestinian concerns if he does."

Mr Indyk advised against evacuating Israeli settlements in the West Bank and Gaza without an Israel-Palestinian accord, though his government has traditionally called the settlements obstacles to peace.

He said any unilateral concession would appear as weakness in the eyes of the Palestinians and generate more violence.

Key player

Israeli pollsters regularly ask whether people would be prepared to remove settlements in a unilateral separation plan. Recent polls show about half are in favour.

Mr Indyk, appointed ambassador to Israel twice by ex-US President Bill Clinton, has been a key player in Israeli-Palestinian peace efforts.

Born in England and raised in Australia, he plans to join the Brookings Institution, a leading Washington policy think-tank.