Israeli security officials say they plan to intensify their targeted attacks on Palestinian militants. News of the stepped up pace in such operations follows a suicide attack in the Israeli port of Ashdod on Sunday, in which 10 people died.

News agencies quote unnamed Israeli security sources as saying Palestinian militants should expect even harsher retaliation in the days ahead.

The sources say there will be targeted killings and what was termed other measures taken against militants and that the targets will be from the top down.

The same sources were reported as saying that an attack on Sheikh Ahmed Yassin, spiritual leader of the Palestinian militant group Hamas, could not be ruled out.

One member of the Israeli parliament has called on the government to take action against Sheikh Yassin and Palestinian leader Yasser Arafat as well. Avigdor Lieberman of the right wing National Union party said that since responsibility for Sunday's bombing was claimed by both Hamas and the Al Aqsa Martyrs Brigades, an offshoot of Mr. Arafat's Fatah Movement, then the leaders of those groups should bear the consequences.

Palestinians call the Israeli policy of targeted assassinations state-sponsored terrorism. Israel says the policy is self defense.

Just hours after two suicide bombers blew themselves up on Sunday, Israeli aircraft struck suspected Hamas targets in the Gaza strip. One man was reported wounded in the Israeli strike.

Reports say that the apparent target for Sunday's suicide bombing attack is of particular concern, as it demonstrates a shift away from bombings aimed at killing dozens to attacks that could kill hundreds.

In the incident, one of the bombers managed to get inside a security zone at the strategically important port of Ashdod and was reported to have asked directions to a large tank storing explosive chemicals. For unknown reasons the bomber did not try to make his way to the tank but instead blew himself up near a group of workers gathered outside a machine shop. Moments later a second bomber detonated his explosives on the sidewalk in front of a storage area next to the port. The attackers were from the Jabalya refugee camp in the Gaza Strip. Their attack marked the first time Palestinians from the fenced-in Strip were able to enter Israel and carry out a bombing, since the Israeli-Palestinian violence erupted in September 2000.