GAZA CITY, Gaza Strip - Hamas threatened revenge Monday, after 14 Palestinians were killed in the deadliest Israeli raid in Gaza in 17 months - part of an upsurge in bloodshed linked to a proposed Israeli withdrawal from the coastal strip.

Among the dead were 11 militants and three boys between the ages of 8 and 15, and 81 people were wounded. The fighting near the Bureij refugee camp Sunday pitted hundreds of Palestinians with assault rifles, anti-tank missiles and grenade launchers against Israeli snipers and troops firing from helicopters and tanks.

In new fighting today, a 16-year-old Palestinian was killed by army fire.

The spike of violence in Gaza - two recent Israeli air strikes and a complex attack on an Israeli army post by militants - came weeks after Israeli Prime Minister Ariel Sharon said he would withdraw from most of the strip if peace efforts remained stuck.

Each side now seems to be positioning itself to claim withdrawal as a victory - Israel by pounding the militants hard before a pullout, and the armed groups by stepping up attacks to create the impression they are chasing the Israelis out.

Sunday's raid of the Bureij camp appeared mainly aimed at drawing out militants; troops found no weapons and made no arrests.

Alon Ben-David, military commentator for Israel TV's Channel 10, said the purpose of such raids is to "kill as many armed Palestinians as possible."

"It's a ritual in which everything is pre-planned. The army goes in, stations its snipers, then a convoy of armored vehicles moves in," Ben-David told Israel Army Radio. "The Palestinians don't see the snipers, they begin to fire on armored vehicles, and then they get hit."

Israeli military officials said the raid was meant to put the militants on the defensive and prevent them from carrying out attacks on Israelis. However, the Gaza Strip is fenced in, and no Palestinian from Gaza has managed to sneak away to carry out a suicide bombing in Israel in 41 months of fighting.

The only exception came in April 2003 when two British Muslims, who were given their instructions in Gaza, crossed into Israel and one blew himself up in a Tel Aviv pub, killing three Israelis and wounding 50.

The Islamic militant group Hamas today belatedly claimed responsibility for that attack, after initially denying involvement, presumably to signal to Israel that despite logistical problems, it could launch bombings from Gaza.

Hamas said the pub bombing was a message to Israel that the group "has many options to fight against you as long as you are occupying our land and committing massacres against our people."

Hamas also released a farewell video in which one of the Britons, Omar Khan Sharif, from Derby in central England, launched into a tirade in English against Israel and what he said was a world indifferent to Palestinian suffering.