Senators from both parties say President Bush must step up his involvement in the Middle East peace process to try to halt violence in Israel and the West Bank.

Sen. Joseph Lieberman said he is seeking ``much bolder moves'' from the administration.

``I think it's time, with all respect to (U.S. envoy Anthony Zinni), that the president ask Secretary (of State Colin) Powell, who has such great stature throughout the world, to go to the Middle East,'' Lieberman, D-Conn., said on  Fox News Sunday. Zinni is in the region trying to arrange a cease-fire.

Escalating Middle East violence shadowed Bush's Easter weekend in Texas. In the first attack Sunday, a Palestinian suicide bomber killed himself and 14 Israelis and wounded more than 40 in the Israeli city of Haifa. Later, a bomber blew himself up in the Jewish settlement of Efrat in the West Bank. Four people were wounded.

Meanwhile, witnesses and Palestinian officials said Israeli soldiers opened fire on and killed five policeman when the Palestinians tried to surrender in Ramallah.

Bush said Sunday that the suicide bombings in Israel would not discourage his Mideast peacemaking efforts.

``The president condemns these acts of terrorism,'' White House spokesman Gordon Johndroe said after the second bombing. ``The president will not let these latest attacks deter him from the pursuit of peace.''

Bush called five world leaders on Saturday, but none Sunday. He spoke with national security adviser Condoleezza Rice after the first bombing, just before he attended Easter services at a church near his Crawford, Texas, ranch, Johndroe said.

The administration offered no new initiatives and said Zinni would remain in the region

Sen. Arlen Specter, R-Pa., said Bush must get more deeply involved.

``These suicide bombers are acting now to destroy the peace process,'' said Specter, who just returned from the Middle East, where he met with leaders including Arafat.

``I think we need to move aggressively with the Arab countries, where we think the financing is coming from,'' Specter said on CBS' Face the Nation.

Senate Foreign Relations Committee Chairman Joseph Biden said the administration should offer a broad peace pact that includes Arab countries.

``I think there needs to be something dramatic done, and that means the president has to step up his involvement,'' Biden, D-Del., told CBS.

Lieberman said there has been ``some inconsistency'' in the administration's policy in the past few weeks.

``I mean, the fact that Secretary Powell made a strong statement against terrorism on Friday, ... suicide bombing by the Palestinians against innocent Israelis, and then late Friday night or early Saturday morning the United States delegate to the United Nations ... Security Council voted for a resolution calling on Israel to withdraw,'' Lieberman said.

``And then Saturday morning, President Bush again said that (Palestinian Authority) Chairman (Yasser) Arafat could do a lot more to stop terrorism.''

But Sens. Mitch McConnell, R-Ky., and Russ Feingold, D-Wis., said they think Bush is doing all he can.

``I think the Clinton administration did everything it could to resolve this and I frankly think the Bush administration is trying everything it knows,'' Feingold said. ``This is one of the toughest problems that has ever existed in our foreign policy.''