GAZA CITY, Gaza Strip — Israeli troops conducted a grim house-to-house search for their comrades' remains here Tuesday night after Palestinian militants blew up an Israeli troop carrier and then said they had made off with body parts of the six soldiers killed inside.
At least seven Palestinians were also killed as Israeli soldiers unleashed machine-gun fire from tanks and rockets from helicopter gunships.
The soldiers entered Gaza City during a raid that began overnight on Monday to destroy workshops that the army said served as weapons factories. But what began as an almost routine raid gave way to an anxious recovery mission after Israel suffered the largest loss of soldiers' lives in a single operation in 18 months.
Palestinians said they hoped to trade the soldiers' body parts for prisoners held by Israel, but Israel immediately rejected any such exchange.
"They were able to take parts of bodies, hands, brains," said Salama Hamad, 32, a fighter for the militant group Hamas. "We're going to ask for an exchange of prisoners."
Similar tactics were used by the Lebanese guerrilla organization Hezbollah during Israel's 18-year occupation of southern Lebanon, which ended in a unilateral Israeli withdrawal four years ago.
Two other Palestinian militant groups, Islamic Jihad and Al Aqsa Martyrs Brigades, also claimed responsibility for destroying the Israeli vehicle and seizing soldiers' remains.
The Israeli army chief of staff, Lt. Gen. Moshe Yaalon, said the army "will not show any forgiveness toward those who are responsible."
Raanan Gissin, a spokesman for Prime Minister Ariel Sharon, said the troops would stay in Gaza "until we exhaust all the possibilities to return the bodies, to bring them a decent burial in Israel."
That raised the possibility that soldiers could continue to operate for days within Gaza City, in a neighborhood that is a militant stronghold.
The Israeli military enlisted the International Committee of the Red Cross to help locate and retrieve the soldiers' remains, but Simon Schorno, a spokesman for the organization, said, "We have nothing at this point."
Yasser Arafat, the Palestinian leader, issued a statement saying the Palestinian Authority was in contact with "our brothers in Gaza" and trying to end the impasse over body parts "according to religious and humanitarian traditions."
Palestinian officials and journalists said the Palestinian Authority was trying to suppress television pictures of the soldiers' remains, out of concern that it would further inflame the confrontation and harm Palestinians' image.
But al-Jazeera, the Arabic-language television channel, broadcast what it said was two Islamic Jihad militants displaying what they called the head of an Israeli soldier, resting on a table in front of them.