Israeli forces have entered Palestinian areas in the West Bank to arrest suspected militants.
Israeli leaders say they doubt they could comply with a US request to ease restrictions on Palestinians after sending soldiers to the village of Tamoun.
Israel's Foreign Minister Mr Shimon Peres said the operation was ordered because Tamoun is "a concentration of people who are planning attacks in Israel".
Mr Peres said the Israeli military "had several successes in preventing infiltrations in the last two or three days".
Tamoun is six miles from the Jewish settlement of Hamra, where an armed Palestinian shot dead a soldier, a woman and her disabled daughter before soldiers killed him.
Israeli forces have also entered a Palestinian neighbourhood in the city of Hebron and arrested a leading activist from the militant Islamic Jihad, Mr Jamal Shehadeh, the military said.
A statement said Palestinians fired on the soldiers as they left but that no one was hurt.
After daybreak, two Israeli tanks and a bulldozer entered the city of Nablus, taking over the roof of a building, witnesses said.
The incursions come the day after Israeli helicopters fired missiles at a Palestinian security compound in Nablus. The Israeli military said the air strike was retaliation for the attack in Hamra.
Elsewhere a Palestinian man was killed overnight in an explosion at an Israeli army checkpoint outside the West Bank city of Bethlehem, a Palestinian security official said.
The family of Ayhab Rassas (23) of Bethlehem said they believed he had carried out a suicide bombing on Thursday night, but the Israeli army originally cast doubt on that and reported no casualties in the explosion.
Colonel Farouk Amin of Bethlehem's security coordination office said his Israeli counterparts later informed him that the remains of a body had been found at the site of the blast.
Israel Radio said it appeared the man was killed when the bomb he was carrying went off prematurely.
Meanwhile Israeli troops occupying the foothills of the Golan Heights shelled the edge of a south Lebanese village today, witnesses said. A Reuters correspondent said Israeli soldiers in the disputed Shebaa Farms area fired machineguns and several shells at the outskirts of Kfar Shouba village in Lebanon.
PA