Israeli troops shot and killed a Palestinian policeman during a raid on a West Bank town in what the Israeli army said was a retaliation for a suicide bombing that dealt a blow to a five-month-old ceasefire.
The pre-dawn operation in Tulkarm came hours after an Islamic Jihad militant from the area blew himself up in the nearby Israeli city of Netanya. Two Israeli women were killed outright in that attack, and a third died in hospital, medics said.
Israel has now sealed off the Palestinian territories today, barring any Palestinian from entry into Israel from the West Bank and Gaza, the army said, adding that the measure would remain in effect "until a renewed security assessment is made."
Witnesses said some 20 military vehicles swept into Tulkarm, which had been formally under Palestinian security control as part of a ceasefire declared by President Mahmoud Abbas and Israeli Prime Minister Ariel Sharon in February.
Troops fired at a Palestinian security post, killing a policeman in what witnesses called an unprovoked attack. Israeli military sources claimed the army shot back after two soldiers were wounded by fire from Palestinian gunmen.
"This operation was mounted in order to carry out pinpoint arrests of the Islamic Jihad terrorists behind the Netanya suicide bombing that killed three Israeli civilians," a military source said.
Brig.-Gen. Yair Golan, the commander of Israeli forces in the West Bank, told Israel Radio he expected the operation to last for days. "We can not achiever our aims in a matter of hours," he said.
Violence has fallen since the truce took hold, despite sporadic Israeli raids in the occupied West Bank and Gaza Strip as well as shootings and mortar attacks by Palestinian fighters.
New bloodshed could complicate Israel's plan to withdraw from Gaza next month, seen as a possible spur to peacemaking.
Abbas condemned the Netanya bombing as "idiotic", especially given the Gaza withdrawal plan, and vowed to punish the planners. Israel repeated its demand for him to dismantle the armed factions, words echoed by the United States.
"We are calling upon everyone to react strongly to these terrorist incidents. We will be in touch with, and have been in touch with the Palestinian Authority on this matter," US Secretary of State Condoleezza Rice told reporters in Seoul.