Israeli tanks move into Hebron

Israeli troops stand guard Monday outside Arafat's compound in Ramallah.

HEBRON, West Bank (CNN) -- At least two Palestinian policemen were killed early Tuesday when Israeli troops, tanks and armored vehicles entered this West Bank city.

The latest incursion came just hours after President Bush unveiled his plan to end the violence in the region, calling for an Israeli pullback and new Palestinian leadership leading to an independent Palestinian state. (Full story)

More than 60 armored vehicles entered the West Bank city, with about half surrounding the governor's compound, which is Palestinian Authority leader Yasser Arafat's headquarters when he is in Hebron, the sources said.

The two policemen died when gunfire broke out as the compound was surrounded, the sources said. About 100 Palestinian policemen who were inside the compound were being taken away by bus.

Bush, in a White House speech Monday, said he believed an agreement to create an independent Palestinian state could be reached in three years, if the Palestinians choose new leaders and reform their government.

While not mentioning Arafat by name, Bush made it clear he believes the current Palestinian leadership is too compromised by association with terrorist groups to lead a program of reform.

"Today, Palestinian authorities are encouraging, not opposing, terrorism," he said. "The United States will not support the establishment of a Palestinian state until its leaders engage in a sustained fight against the terrorists and dismantle their infrastructure."

Sharon promises 'massive military action'

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Earlier Monday, in remarks to his Likud faction in the Israeli Knesset, Prime Minister Ariel Sharon said Israel had begun parallel anti-terrorist offensives in the West Bank and Gaza, including a "massive military action" against the Islamic militant group Hamas.

"The information that they [terrorists] are planning to carry out more attacks against Israel has led us to decide on a major military offensive entering into all the [West Bank] towns and staying there indefinitely," Sharon said.

"Collaterally, we are preparing a massive military action against the Hamas in the Gaza Strip, the beginning of which you saw [Monday] morning."

The past week has seen 31 Israelis killed in three terror attacks, including the two suicide bombings and a shooting attack in an Israeli settlement in the West Bank.

New suicide attacks threatened

In Gaza, Yasser Rizek, a senior activist in the Izzedine Al-Qassam Brigades, Hamas' military wing, was killed in an Israeli missile strike, Israeli and Palestinian sources said.

Hamas is an Islamic militant group labeled by the U.S. State Department as a terrorist organization. Hamas has claimed many suicide bombings in Israel.

Another airstrike casualty was identified as Amir Qufeh, a Hamas member, Palestinian sources said. The four others killed were not affiliated with any political group, sources said.

Hospital officials in Rafah confirmed the casualties, and Palestinian security sources confirmed the attack. Ten people -- all reportedly bystanders -- were wounded. One car was private, and the other was a taxi.

Meanwhile, Palestinian authorities issued an order placing Sheikh Ahmed Yassin, the spiritual leader of Hamas, under house arrest at his Gaza home. He previously has been placed under house arrest. In addition, Palestinian authorities arrested 15 Hamas members Sunday.

In a statement to news agencies, the Izzedine Al-Qassam Brigades threatened to step up suicide attacks in response to the Israeli strike and Yassin's house arrest.

"We emphasize our right to continue the jihad and resistance and to intensify the martyrdom operations as a reaction to the policy of the occupation and the [Palestinian] Authority," the statement said.

Military sources said Rizek was behind a January 9 attack at an outpost near an Israeli kibbutz. Four soldiers were killed and two wounded in that attack, and sources said Rizek also has been involved in a long list of attacks against Israel Defense Forces.

The Israeli military said that in recent days Rizek was planning to smuggle attackers from Gaza into Israel to carry out suicide attacks. Rizek was in an Israeli prison in the early 1990s.

-- CNN Correspondent Matthew Chance contributed to this report.