Israeli forces today entered the West Bank city of Hebron and arrested more than 100 Palestinians, officials said.
The Israeli army said the raid, which comes days after Israeli troops shot and killed Mr Abdullah Kawasme, the Hamas leader in the city, targeted militants in the Hamas.
Troops also closed off the old city of Nablus and searched for terror suspects, the army said. Several suspected militants were arrested.
Yesterday it was reported Hamas and other militant groups were close to agreeing to halt attacks on Israelis, Palestinian officials said.
But Israel warned it may not accept what it considers a tactical ceasefire meant to give the militias time to regroup for more shootings and bombings.
The terms of the emerging deal between Palestinian Prime Minister Mr Mahmoud Abbas and the militias were not clear. One Palestinian mediator said the truce will be open-ended and apply to Israel, and also the West Bank and Gaza Strip - a key condition for Israel.
However, a leader of one of the armed groups said on condition of anonymity that Hamas will only accept a three-month truce. Leaders of the smaller Islamic Jihad group are trying to persuade activists to accept a limited deal, but are facing stiff opposition, he said.
Palestinian officials, including Foreign Minister Mr Nabil Shaath and Cabinet Minister Mr Yasser Abed Rabbo, were optimistic, saying they expect a positive response by the militias.
A Hamas leader, Mr Mahmoud Zahar, said the announcement would not come yesterday, contradicting assessments by Palestinian officials but said that "the decision will hopefully come very soon".
Washington has urged Arab nations to stop funding Hamas, Syria closed the offices of Palestinian militant groups and Israel threatened to assassinate Hamas leaders. Last week, Secretary of State Mr Colin Powell called Hamas an "enemy of peace".
A Palestinian uprising leader, Mr Marwan Barghouti, has also lent his prestige to the talks, writing ceasefire proposals from his Israeli prison cell and forwarding them to Mr Khaled Mashal, a Hamas leader based in Syria, according to one source.