Israeli Prime Minister Ariel Sharon vows to target the leaders of the extremist group, Islamic Jihad, which claimed responsibility for Tuesday's suicide bombing in the coastal city of Netanya that killed four people and injured dozens more. Israel has already responded to the bombing by closing off the West Bank and Gaza Strip.

Mr. Sharon told reporters he's ordered security forces to step up operations against Islamic Jihad and "hit the leadership."

The comment would signal a return to Israel's controversial policy of targeted assassinations of militant leaders - a practice it suspended following a truce with the Palestinians concluded in early February.

Defense Minister Shaul Mofaz said the decision is justified.

Islamic Jihad, he said, made a strategic decision to commit a terrorist attack. Israel, he said, is going to act at any place, at any time against Islamic Jihad.

Shortly after Tuesday evening's bombing Israel sealed off the West Bank and Gaza Strip and security forces moved back into Tulkarem, re-occupying the West Bank city they had turned over to Palestinian control just four months ago. Troops rounded up a number of Islamic Jihad militants and the military said the security sweep could last several days.

Speaking on Israel radio, Yuval Steinitz, head of the Foreign Affairs and Defense committee in Israel's parliament says Tuesday's suicide attack should come as no surprise and he puts the blame on Palestinian Prime Minister Mahmoud Abbas, also known as Abu Mazen.

"Well, unfortunately this was forthcoming, taking into account that Abu Mazen was doing and is doing nothing to disarm the terrorists," said Yuval Steinitz.

Palestinian leaders were quick to condemn the Netanya bombing and President Abbas has vowed to track down those responsible.

Palestinian government spokesman, Samir Hilleleh said action against the militants was imminent.

Speaking on Palestinian radio, Mr. Hilleleh said it will soon be very clear that there is one Authority and one gun. He said this will be implemented soon and without exception or excuses.

President Abbas spoke of "one Authority - one weapon" when he took office in January. It was to be a signal to the various militant groups that only the Palestinian Authority would be in charge and only its forces would be allowed to carry weapons. But, Mr. Abbas has avoided going up directly against the militants, opting instead for a dialogue to coax them into a truce with Israel and try to bring them into the political process.

Tuesday's Netanya bombing now increases pressure on President Abbas to move more aggressively.