Israeli tanks have gone into Jenin, two days after a huge suicide bomb attack.
Soldiers fired in the air as the 30-vehicle column moved through the town but no fighting was reported. The army said the force was on routine patrol.
Israeli tanks and troops blew up buildings and shelled Mr Yasser Arafat's living quarters yesterday in a six-hour reprisal raid on his presidential compound after a bombing killed 17 Israelis, many of them soldiers, on a bus in the Galilee a day earlier.
Mr Arafat emerged unhurt and accused Israel of "fascism" after the force pulled out of Ramallah.
The bombing and the army push into Mr Arafat's compound before a visit by Israeli Prime Minister Ariel Sharon to Washington next week undercut intensified international diplomacy aimed at reviving peace talks.
Egyptian President Hosni Mubarak, who holds talks today and tomorrow in the US with President Bush, called for Washington to take the lead in seeking a rapid resolution of the Israeli-Palestinian conflict.
The White House said it was not clear what Israel's aims were in carrying out the Ramallah raid, stressing that both sides needed to take "constructive steps" toward peacemaking.
"You would have to check with the Israelis to ask them what the objective for the incursion was last night. I don't know what the objective of the incursion was last night," White House National Security Council spokesman Mr Sean McCormack said.