Ramallah operation ups stakes

The Ramallah operation is the Israeli army's biggest in 20 years

BBC News Online's Tarik Kafala

Ramallah, overrun by more than 150 Israeli tanks and armoured vehicles on Tuesday, is the most important Palestinian city in the West Bank.

	Ramallah: Population 40,000. 220,000 people live in Ramallah district Al-Amari refugee camp: Established in 1949. Now home to 7,273 officially registered refugees

As well as housing Yasser Arafat's West Bank headquarters, it is the area's commercial and political centre, and its most populous city.

By invading most of Ramallah with such a large force, the Israeli Government is - however briefly - overturning the practical structure of Palestinian self-rule.

This was the largest Israeli deployment since the start of the Palestinian uprising - and the biggest military operation since the invasion of Lebanon 20 years ago.

Palestinians are saying that the operations amount to "complete re-occupation" of the West Bank.

This may be a short-lived state of affairs, but once again a threshold in the conflict seems to have been passed.

City under siege

Ramallah also houses the bulk of the Palestinian Authority's (PA) security forces and police, but they do not appear to have come out in force to fight the Israeli army.

The Israeli army is expected to meet heavy resistance in the al-Amari refugee camp

The city has been under siege since the beginning of the intifada, and been hit by repeated Israeli air raids.

In recent months Israeli tanks have come right up to Mr Arafat's headquarters in Ramallah, close to the city centre.

A resident of Ramallah who spoke to BBC News Online said that most of the city had been invaded and that people were not going out.

There had not been heavy resistance, he said, but that was expected if the Israeli troops take over what appears to be one of their main targets in the city, the al-Amari refugee camp.

One 15-year-old who fled the camp during the night told the French news agency AFP that most men over the age of 15 had left for fear of being arrested.

"They're inside searching and destroying houses... Mostly old men, women and children are still inside," he said.

Three suicide bombers - one a woman - have launched recent attacks against Israeli targets from al-Amari.

Tactical change

Recent Israeli military operations into cities and refugee camps seem to represent a change in Israeli tactics in response to a spate of devastating Palestinian attacks on civilian and military targets.

Instead of rocket attacks and air strikes against largely empty buildings, Israel is going after what it calls the "infrastructure of terror".

But the operations also have political or diplomatic elements. They come just ahead of the return to the region of US envoy General Anthony Zinni for a third attempt to nudge both sides towards a ceasefire and talks.

Officials say the offensive into Ramallah will continue, at least until he arrives.

Israeli newspaper commentators suggest the government wants to have substantial areas of Palestinian territory, areas under Palestinian security and administrative control, in its hands.

The Israeli Government can then appear to be making concessions by withdrawing, just ahead of General Zinni's arrival.