Israeli troops killed at least 14 Palestinians during fierce gun battles with militants during raids into two refugee camps in the Gaza Strip. At least three children and 10 known Palestinian militants are reported to be among the dead.
The Israeli army says at least nine of those killed in the two operations were members of Hamas, a group that has carried out frequent suicide bombings and other terrorist attacks in Israel.
Both Hamas and the Islamic Jihad, another group classified by the State Department as a terrorist organization, have promised they will kill more Israelis to retaliate for the operation.
Israeli troops have withdrawn from the Bureij and Nusseirat refugee camps in Gaza, where they fought for hours with Palestinian gunmen.
Saturday, six Palestinians were killed during a failed assault on Israeli military targets at the Erez crossing point into Gaza.
Chief Palestinian negotiator Saeb Erekat strongly condemned Sunday's raids. He accused Israel of destroying the Gaza Strip even as it is preparing to withdraw troops and Jewish settlers from the territory.
Israeli Government spokesman Avi Pazner rejected the charges. He says the refugee camps have become bases for terrorism.
Mr. Pazner says that the Israeli military actions are preventing acts of Palestinian terror and saving the lives of Israeli citizens.
Israeli Prime Minister Ariel Sharon has said he would evacuate most, if not all, Jewish settlements from Gaza if there is no sign soon of Palestinians reviving peace talks.
Some observers say Israel is intensifying its military operations before a planned withdrawal from Gaza to avoid the impression it is fleeing the area because of pressure from armed Palestinian groups.