Israeli soldiers painted their faces outside the West Bank city of Qalqilya on Sunday night as Israeli tanks entered the city.

Prime Minister Ariel Sharon addressed a nation rattled by five suicide bombings in five days, including two attacks today that killed 14 Israelis.

An injured victim is evacuated from the scene of a suicide bombing in Haifa today, the fourth Palestinian attack against Israel in five days.

JERUSALEM, March 31 — Calling Yasir Arafat "the enemy of the entire free world," Prime Minister Ariel Sharon declared Israel today to be in a war. He spoke after a suicide bomber blew himself apart in a restaurant in the seaside city of Haifa, killing at least 14 other people, while Israel was tightening its ring of tanks and rifles around the Palestinian leader.

Mr. Sharon has made similarly bellicose statements about Mr. Arafat in the past, but his terse remarks tonight seemed intended to prepare Israel and the world for a major new assault on the West Bank, and possibly for a raid into Mr. Arafat's office itself.

"The state of Israel is in a war, a war against terrorism," he said. "This is a war over our home."

Israeli officials have said Mr. Arafat is hiding wanted men in the few rooms he still controls in his crumbling compound in the West Bank city of Ramallah.

Late tonight, a column of Israeli tanks and armored bulldozers entered Palestinian-controlled territory in Qalqilya, in the West Bank, northeast of Tel Aviv.

Palestinian and other Arab leaders increasingly blamed the United States for the Palestinians' predicament, after President Bush gave his qualified blessing on Saturday for the Israeli assault and American diplomacy remained largely silent for another day.

Israeli troops fired again toward Mr. Arafat's office today. The army said soldiers opened fire after an armed man stepped outside, but Palestinians inside the compound disputed the assertion, saying that Mr. Arafat's guards repelled an attempt by soldiers to storm the office.

In his Easter message, Pope John Paul II appealed for an end to "the dramatic spiral of the imposition of will by force and killings that bloody the Holy Land. [Page A4]

"It seems that war has been declared on peace," the pope said.

The Israeli government continued to say that its soldiers were taking precautions not to harm Mr. Arafat himself. But Brig. Gen. Ron Kitri, the army's top spokesman, said, "It must be remembered that Arafat is not sitting in a monastery. He is surrounded by armed Palestinian fighters."

Waving white cloths, a group of about 40 foreign members of a pro-Palestinian group walked through the Israeli lines today to join Mr. Arafat in his office. Most of them stayed inside, apparently intending to serve as a human shield, which caused consternation at the top levels of the Israeli government.

The streets of Ramallah were empty once again today, but so were the streets and sidewalks of Jerusalem, on the first day of the Israeli work week. People rushed to and from work without lingering on street corners or in cafes, where a terrorist might strike. The skies were dark and full of dust thrown up by a fierce, cold wind.

In his remarks tonight, an address to his nation that lasted less than four minutes, Mr. Sharon was clearly seeking to line himself up with the United States in a global fight against terrorism that, for him, is centered on Ramallah. He said Mr. Arafat was "at the head of a coalition of terrorism" and "operating a strategy of terrorism." He called the Palestinian leader "an obstacle to peace in the Middle East" and "a danger to the whole region."

With rising alarm, Arab leaders in recent days have called the Israeli assault on Mr. Arafat's compound a threat to regional stability.

Palestinian officials called Mr. Sharon's statement a declaration of war. Nabil Aburdeineh, a close aide to Mr. Arafat who has stayed at his side in Ramallah, said Mr. Sharon was trying "to boost the collapsed morale of his people.

"The Israelis should understand that the Palestinian people will be steadfast and will not surrender, and that they are confident that victory is coming," he said.

The blast in Haifa today blew the roof off the restaurant, which was operated by a family of Israeli Arabs. Several Israeli Arabs were among the dead, the police said, though officials were still trying to identify some remains late tonight. Haifa is one of the few areas where Israeli Jews and Arabs live in relative harmony, and some survivors said they had believed that they were safe because no bomber would risk killing Arabs.

The Islamic group Hamas took responsibility for the attack. It called the victims "the thieves of our homeland" and the act a retaliation for Israeli invasions of Ramallah, Bethlehem and other towns.

The bomber was identified as a 23-year-old Palestinian from the refugee camp in the nearby city of Jenin.

Less than two hours later, another suicide bomber struck, the fifth in five days. He killed himself and wounded at least four others in the settlement of Efrat, in the West Bank south of Bethlehem.

At least 44 Israeli civilians have died in Palestinian attacks since Wednesday night, when a suicide bomber killed himself and 22 other people who were gathered for a Passover Seder in Netanya.

Marwan Barghouti, the West Bank leader of Yasir Arafat's Fatah faction, said the recent Palestinian attacks demonstrated that, "If your tanks are able to impose siege on President Yasir Arafat, our heroes succeeded in storming the Israeli cities."

Mr. Barghouti has said previously that he believes that Palestinian militants should confine their attacks to the West Bank and Gaza Strip, the lands that Israel occupied in the 1967 war and that he sees as the future home of a Palestinian state. But in his comments today, on Palestinian television, he warned: "Our heroes will penetrate your streets, your cities. You will not enjoy security and peace unless our people enjoy peace and freedom."

Implicating the United States in the captivity of Mr. Arafat, he said: "This aggression is by an American decision, and American weapons. America now is the one providing cover for terrorism and supporting terrorism."

Mr. Arafat said that he spoke by telephone with Secretary of State Colin L. Powell and told him, "We need the urgent sending of international forces to stop this aggression and military escalation."

Mr. Bush, speaking from his Texas ranch, said on Saturday that Mr. Arafat should be doing more to stop violence and that he understood "Israel's need to defend herself."

For a third day, Israeli troops conducted house-to-house searches in Ramallah, rounding up Palestinian teenagers and men in what the army called a hunt for terrorists.

Nidal Abdallah, an 11th-grade student from Al Bireh, which adjoins Ramallah, said he was held overnight by Israeli soldiers after complying when troops broadcast a summons on Wednesday for boys and men between the ages of 15 and 45 to assemble at a school. He said that he sat up all night in a lighted classroom with other men and that he was never questioned.

"Sometimes they'd call people out and take them outside and hit them a little if you threw a smart remark," said Nidal, an American who divides his time, with his family, between Ramallah and Cicero, Ill. "They would smack him around, not too hard, slap him on the face. In the morning they let us out."

The matter of the pro-Palestinian group that joined Mr. Arafat in his office came up in a lengthy meeting on Sunday afternoon of Israel's senior leadership. Mr. Sharon promised that no such group would be permitted to pass again, one Israeli official said. The army said it had arrested 13 members of the group who left the compound, accusing them of defying its closure of Ramallah.

The Israeli government also increased its pressure on foreign journalists to leave Ramallah. Government officials threatened to remove reporters found there and to strip them of their press credentials. In Jerusalem, they threatened to fine any news organization $15,000 if it was found harboring Palestinians "without the proper permits" in one building housing news bureaus.

Many news organizations here employ Palestinian journalists.

In his speech on Sunday night, Mr. Sharon promised to strike "the terror infrastructure" at its foundations because that was the only way to achieve a cease-fire and then, ultimately, peace.

To many Israelis and Palestinians, Mr. Sharon's language and orders increasingly bring to mind Israel's invasion of Lebanon 20 years ago. "It was our business never to allow a terrorist infrastructure that would threaten Israel's security to be built in Lebanon again," Mr. Sharon wrote of that operation, in his autobiography, "Warrior."

In 1982, Israeli forces led by Mr. Sharon, then the defense minister, pushed into Lebanon in what was presented as "Operation Peace for Galilee," a brief raid to clear away the northern border.

But the tanks and troops kept moving until they were besieging the capital, Beirut, itself. In "Warrior," Mr. Sharon recalled feeling frustrated by American efforts to bring about a cease-fire. He argued that the Palestine Liberation Organization had built an "actual state" in Lebanon that amounted to "a kingdom of terror."

Mr. Sharon succeeded in expelling Mr. Arafat from Beirut, and he then met with about 30 Palestinian leaders in the West Bank, he recalled, in hopes of opening "a new era" in relations.

Palestinian officials say Mr. Sharon is pursuing the same strategy now, hoping to expel or kill Mr. Arafat and then raise up a new, more tractable Palestinian leadership.

"For me it is not the first time," Mr. Arafat told CNN on Sunday, referring to his survival of the siege in Beirut, which he recalls as a triumph over Mr. Sharon. "He has to remember what happened in 88 days in Beirut."

The prime minister argued in a cabinet meeting Friday for Mr. Arafat's expulsion, top Israeli officials said, but was opposed by leaders of the moderate Labor Party and by his own security chiefs. The security officials said Mr. Arafat would be more dangerous abroad than under Israeli lock and key in Ramallah.