Washington ? U.S. officials said Friday envoy Anthony Zinni would remain in the Mideast and continue to talk with Palestinians and Israelis despite new violence and Israeli attacks on Yasser Arafat’s compound that made the situation newly volatile.

It seemed apparent, however, that the string of latest Palestinian attacks, the strong Israeli reprisals and new and widespread protests across the Mideast had largely blunted the hopeful momentum U.S. officials had cited Thursday, when Arabs endorsed a Saudi peace proposal.

“We have followed developments overnight and this morning in the Middle East,” said White House spokesman Sean McCormack. “Gen. Zinni remains in the region, is in contact with the parties and continues his work.”

McCormack said U.S. officials “are monitoring events very closely and are assessing appropriate responses.”

President Bush was watching the situation from his Crawford, Texas ranch, and held a longer-than-usual meeting by videophone of his National Security Council a session dominated by the Middle East, said another White House spokesman, Gordon Johndroe.

He declined to offer the president’s view of the spiraling violence, and knew of no phone calls Bush or other top officials had made Friday.

Israel declared Arafat an enemy Friday and sent troops and tanks to break into his West Bank compound, battling his security forces and shelling the buildings. Arafat took refuge in a windowless, ground-floor room, although Israeli officials insisted they were not trying to hurt him.

Israel launched the large-scale military operation in response to the latest string of deadly Palestinian attacks, including a Passover attack that killed 22. In all, at least 27 Israeli civilians have been killed in the string of suicide attacks the last three days.

Israel’s Cabinet approved an extended military operation and agreed to call up thousands of reserve troops on Friday. Prime Minister Ariel Sharon said Israel had sought a cease-fire in good faith, “but all Israel got in return was terrorism, terrorism and more terrorism.”

Before the Israeli attacks began Friday, U.S. officials had sounded somewhat hopeful about a Saudi peace proposal endorsed Thursday by the Arab League at a summit in Beirut, Lebanon.

State Department spokesman Richard Boucher had said the Arab proposal held out a vision of hope. But U.S. officials also had made clear that ending the violence should remain the top priority.

Secretary of State Colin Powell had called strongly on Arafat in recent days to stop the violence, while U.S. officials also urged restraint on Israel.

Friday’s assault in Ramallah marked the first time Arafat’s office building has been targeted, although Israel has shelled other buildings in the compound in the past 18 months of fighting. Defense Minister Binyamin Ben-Eliezer said there was no intention to harm Arafat, but the fire on his building made the situation volatile.

In Lebanon, Palestinian refugees burned tires to protest the Israeli attack and Arab politicians denounced it.

It is unclear how much more U.S. officials can do after the Bush administration’s public peacemaking efforts of recent weeks were challenged by the Passover attack.

Nevertheless, many both inside and outside the administration insist the United States is still the only party that both sides trust and thus the only who can bring them back from the brink of violence.