Israeli troops blew up two apartment buildings in a Gaza Strip refugee camp Wednesday, just hours after undercover forces killed the brother of a radical Palestinian leader during an arrest raid in the West Bank.

The Israeli strikes, which came a day after a Hamas sniper killed an Israeli soldier, further undercut shaky attempts to reach a partial truce. However, officials from both sides said Wednesday they were not walking away from the deal.

In the agreement reached earlier this week, Israeli soldiers withdrew from the West Bank town of Bethlehem and were to pull back from positions in Gaza, in exchange for Palestinian efforts to maintain calm in the test areas.

Militant Palestinian groups have rejected the plan and said they would carry out more attacks on Israelis. On Tuesday, a Hamas sniper firing from the Khan Younis refugee camp killed an Israeli soldier guarding nearby Jewish settlements, in what the Islamic militant group said was an attempt to disrupt the truce.

In response, Israeli troops backed by tanks and helicopters blew up a five-story and a six-story building in Khan Yunis in what the army said was an operation to prevent gunmen from firing on nearby Jewish settlements.

A 24-year-old Palestinian was killed when he was struck in the head and back by shrapnel, hospital officials said.

The explosion also damaged eight nearby smaller homes, making them uninhabitable, Khan Younis municipal officials said. In all, 100 people were made homeless — 80 had lived in the smaller homes and 20 in the apartment blocs, the officials said. The two apartment buildings had been largely abandoned in recent months after coming under frequent fire during Israeli raids.

Nawal Hassouneh, 11, picked through the rubble of her one-story home Wednesday, retrieving a tattered school bag her father had bought her a day earlier. "They killed my joy," she said. "I had been so happy about the bag. Now I have no home and no bag."

The soldier killed Tuesday, 19-year-old Kevin Cohen, had immigrated from Iran in 1987. He was in an outpost when a sniper's bullet hit him in the head.

In the past two years of fighting, Israeli troops demolished 75 houses in the part of Khan Younis that abuts the Jewish settlements, municipal officials said. The camp is a stronghold of Palestinian militiamen.

The Gaza raid came hours after Israeli undercover forces shot and killed Mohammed Saadat, brother of Ahmed Saadat, leader of the Popular Front for the Liberation of Palestine, in the West Bank city of Ramallah.

Minutes after the soldiers stormed the house late Tuesday, Mohammed Saadat's bullet-riddled body lay on the ground behind the building. Angry neighbors and relatives shouted and threw rocks at the Israelis, who fired rifles in the air to disperse the crowd.

The Israeli military said the force intended to arrest Saadat, but that he opened fire, wounding two soldiers. Other troops killed Saadat. The statement said Mohammed Saadat was an activist in the PFLP, which claimed responsibility for the assassination of Israeli Tourism Minister Rehavam Zeevi last year.

"Mohammed Saadat was not an innocent man. He was wanted, a senior fugitive, and he was wanted for his own actions and not only for his brother's," the chief army spokeswoman, Brig. Gen. Ruth Yaron, told Israel Army Radio.

Ahmed Saadat is jailed in a Palestinian lockup, under U.S. and British supervision, as part of a deal that ended Israel's monthlong siege of Palestinian leader Yasser Arafat's Ramallah headquarters in May.

Israeli and Palestinian officials traded accusations Wednesday, but said they were not abandoning the fledgling truce agreement for now.

Arafat adviser Nabil Abu Rdeneh said Israel is trying to sabotage the deal by killing Mohammed Saadat. He said that as part of the agreement, Israel must now withdraw from the West Bank town of Hebron.

Raanan Gissin, an adviser to Israeli Prime Minister Ariel Sharon, said a pullback from Hebron is being discussed, on condition the area remained calm. In Gaza, "we're not seeing that at the moment," he said.

Israeli and Palestinian field commanders were to meet later Wednesday to discuss the details of a withdrawal from some positions in Gaza. Israeli troops are concentrated along the main north-south road, which is often blocked by tanks, effectively cutting Gaza in half.

Six of the eight main Palestinian towns and cities in the West Bank remain under Israeli control, after a large-scale invasion in mid-June that followed back-to-back suicide bomb attacks in Jerusalem.