JERUSALEM — Palestinian militant groups threatened Thursday to abandon a fragile cease-fire after Israeli undercover troops shot and killed a wanted Palestinian militant in a West Bank refugee camp.
A series of incidents over the last week has frayed the relative calm that took hold after the election of Palestinian Authority President Mahmoud Abbas in January. Last weekend, Israeli troops shot and killed three Palestinian boys under disputed circumstances in the southern Gaza Strip. Palestinian militants responded with a rain of mortar shells against Jewish settlements. No casualties resulted.
Although the overall level of violence is low compared with the height of the Palestinian intifada, or uprising, it comes against a backdrop of Israel's increasing worry about whether Abbas can rein in the militant groups.
Prime Minister Ariel Sharon sought to raise those concerns in talks Monday with President Bush, but the meeting was dominated by the leaders' clash over Israel's planned expansion of the West Bank's largest Jewish settlement.
Israel identified the slain militant as 23-year-old Ibrahim Hashash of the Al Aqsa Martyrs Brigade. Military sources said he had intended to carry out a suicide attack in Jerusalem in the coming days.
Israeli officials and Palestinian witnesses gave differing accounts of Thursday's confrontation in the Balata refugee camp outside Nablus.
Israeli military sources said Hashash shot at troops who were trying to arrest him and was mortally wounded by return fire. The sources said Hashash was acting in concert with the Lebanon-based militant group Hezbollah, which Israel accuses of trying to "subcontract" attacks inside Israel by Palestinian militants.
Palestinians said plainclothes troops leaped from a car and opened fire without warning.
The Al Aqsa Martyrs Brigade said it would avenge the killing. "Our reaction will be like an earthquake," the Reuters news agency quoted a spokesman as saying.
Hamas, or the Islamic Resistance Movement, condemned what it called Israeli aggression. Ismail Haniya, a Hamas official, told reporters in Gaza that any more such raids would prompt it to "seriously reconsider" a decision by the militant groups, made last month at a conference in Cairo, to halt attacks for the rest of the year.
Israel has called a halt to "targeted killings" of Palestinian militants but reserves the right to target "ticking bombs," those who are believed to be planning an imminent attack.
