Israel launched a military clampdown in the occupied West Bank on Tuesday in the opening stages of what it vowed would be a harsh response to a Palestinian suicide bombing that killed five Israelis.
Prime Minister Ariel Sharon has given the green light for hits on leaders of Islamic Jihad, the group behind Monday's attack in central Israel, amid a re-election campaign against rightist foes who accuse him of being soft on the Palestinians.
"We will do all we can to strike at the attackers," Foreign Minister Silvan Shalom said after Israel's security cabinet approved retaliation plans, which threatened a new spiral of violence that could bury hopes stirred by Israel's Gaza pullout.
Israel's army said it tightened restrictions on Palestinian movement in the West Bank and carried out raids that led to 14 arrests for the bombing at a busy shopping mall in Netanya. The bomber's father and three brothers were detained.
Israel also suspended VIP entry permits for Palestinian officials and would buffer its forces in border areas near the West Bank, Shalom said.
Security sources said Israel wanted to deal a heavy blow to Islamic Jihad, which is sworn to the destruction of the Jewish state, and send a message to the Palestinian President Mahmoud Abbas that he must crack down on militants.
But they said the response would be tempered to avoid drawing in Hamas, a more powerful Islamist group that has largely restrained itself during the cease-fire engineered by Abbas.
"It will be a show of strength but not something that will get out of control," one Israeli security official said.
Shalom said Israel had no plans to re-enter Gaza, which it quit in September after 38 years of occupation. Ground operations would focus on the northern West Bank.
Islamic Jihad said it carried out the attack to avenge Israel's recent killing of senior members.
Gaza-based leaders of the group could not be reached on their mobile phones, suggesting they had switched them off for fear the signal could be used to pinpoint them in an Israeli air strike.
More violence could be politically damaging to both Abbas and Sharon. Abbas is struggling to instil order ahead of a January parliamentary election in which his Fatah party faces a challenge from Hamas. Sharon is seeking re-election in March as head of a new centrist party he founded after carrying out the Gaza pullout over fierce opposition within his rightist Likud party.
He has hinted his new party would be more open to compromise but has refused to resume peace talks with the Palestinians until they disarm militants.
Sharon billed the Gaza withdrawal as "disengagement" from conflict but rightist opponents he faces in the coming election say it rewarded Palestinian violence.
Palestinians accuse Israel of stoking conflict with army raids and settlement expansion in the West Bank where Sharon has vowed to keep large settlement blocs forever.
US Secretary of State Condoleezza Rice condemned the Netanya bombing, the fifth in the Jewish state since a truce was declared in February. "This does call upon the Palestinians to fight terror," she told reporters en route to Berlin.
Sharon's aides reiterated accusations that Syria bore a share of responsibility for the group's bombings, Israel's YnetNews Web site said.
Washington called on Damascus to close Islamic Jihad's offices in the Syrian capital.
The Netanya bomber, from a village near the West Bank town of Tulkarm, was stopped by a security guard before he could enter the mall. But he detonated his explosives, killing the guard and four shoppers and wounding more than 40 people.