JERUSALEM -- Israeli leaders warned Syria yesterday that it bears the blame for a double suicide bombing by Hamas militants because it harbors the group's leadership, and they hinted at possible retaliation.
In a first response to the attack Tuesday that killed 16 people in a southern Israeli city, Israeli troops blew up the home of one of the bombers and isolated the West Bank city of Hebron, where the attackers lived. But Israel was looking farther afield to assign the blame.
''The fact that Hamas is operating from Syria will not grant it immunity," said Ra'anan Gissin, an adviser to Prime Minister Ariel Sharon of Israel.
The overall leader of Hamas, Khaled Mashaal, and his deputies are based in Syria. Earlier this year, Israel assassinated Hamas' founder and his successor in Gaza, throwing the militant Islamic group into temporary disarray. But major decisions are made by Mashaal, not by Hamas leaders in Gaza.
The Israeli Army chief, Lieutenant General Moshe Yaalon, said yesterday that those who support terrorism ''cannot sleep quietly at night," mentioning Palestinian leaders, Lebanese Hezbollah guerrillas, Syria, and Iran.
Sharon added: ''Israel's struggle against terrorism will continue unabated. We will apparently need to decide on additional steps to stop terrorism."
He did not elaborate.
Last Oct. 5, Israeli planes attacked the training camp of another militant group, Islamic Jihad, outside Damascus, the Syrian capital, a day after a suicide bomber blew up a restaurant in the Israeli port city of Haifa, killing 21 people.
But although Israel and Syria are bitter enemies, the airstrike was a rare act of violence. Israel has held Syria's government partly responsible for years of Hezbollah raids from southern Lebanon and has often threatened Syria. But in practice, the Israelis hesitate to provoke a conflict with Syria, and their border has been calm for decades.
Security officials, speaking on condition of anonymity, said Israel would pursue local Hamas leaders and step up military patrols in the sparsely populated, barren southern part of the West Bank. The target of the bombings Tuesday was Beersheba, 15 miles south of the West Bank.
Sharon also pledged to finish the West Bank security barrier, which is aimed at keeping Palestinian suicide bombers from getting into Israel but has drawn international criticism.
Palestinians say the barrier cuts into their territory and separates tens of thousands of people from farmland, hospitals, and services.
''The fence will be completed according to the Cabinet decision, and we are doing all we can to speed up the process as much as possible," Sharon said.
Israel did not impose travel bans across the West Bank in response to the bombings, as it has after previous attacks. Such blanket restrictions proved relatively ineffective in preventing attacks and mostly increased resentment against Israel. Israeli security forces are relying increasingly on pinpoint attacks on militant leaders, mass arrests, and a network of informers.
Security officials said there was concern that a rash of Palestinian attacks could sabotage Sharon's planned withdrawal from the Gaza Strip and parts of the West Bank in 2005. Hard-liners have said a pullback would make it easier for Palestinians to attack Israel.
Israeli military analysts said Beersheba became a target of suicide bombers for the first time because their paths to Israeli cities in the north have been blocked by the separation barrier.