The man’s wife said he was sleeping and she was praying when soldiers burst into the apartment before dawn, entered the bedroom and immediately opened fire. Afterward they asked her for his identity card. She gave her account a few hours later, standing next to the bed, whose mattress, sheets and pillows were soaked in blood. The headboard, an adjacent wardrobe and the ceiling were also spattered with blood and bits of what appeared to be brain matter.

The Israeli military expressed regret but offered no explanation beyond saying that it had been carrying out an arrest operation. It said the West Bank division commander had been ordered to carry out a speedy investigation, with conclusions to be presented as early as next week.

The soldiers were apparently looking for the dead man’s nephew, a Hamas militant who was one of six released from a Palestinian Authority prison on Thursday. He was staying in an apartment on the floor below the slain man’s and was rearrested by the Israeli military soon after the killing. Four of the other released militants were arrested by the Israelis overnight as well.

Friday’s killing was the third death in the West Bank in a week for which the Palestinians blamed the Israelis. Coming after a period of relative calm, the deaths have added to fears of an escalation at a time when Israeli-Palestinian peace talks are stalled. After noon prayers on Friday, the alleyways around the man’s home seethed as hundreds escorted the body from a nearby mosque for burial, chanting, “In blood and spirit, we will redeem you, O martyr!”

Initial reports on Israeli radio suggested that the slain man, Omar al-Qawasmeh, may have run at the soldiers, but the blood soaking the bed and dotting the walls seemed to belie that. His wife, Subhiya Awad al-Qawasmeh, said that the soldiers fired at her husband’s head and upper body. She said they thought he was the nephew, Wael Bitar.

“They came to kill Wael,” she said.

The killing also heightened tensions between the authority, which the West backs, and Hamas, its militant Islamist rival. Hamas accused the Palestinian Authority of collaborating with Israel in the case and bearing joint responsibility for the man’s death. The authority has been reining in Hamas activists and militants in the West Bank since the Islamist group, which won Palestinian parliamentary elections in 2006, seized full control of Gaza a year later. There, Hamas has detained loyalists of Fatah, the dominant party of the authority.

In this case, the authority had just released Mr. Bitar and five others who had been on a hunger strike. The Israeli military said that Mr. Bitar was the assistant of the man who planned a suicide bombing in the southern Israeli town of Dimona in February 2008, in which an Israeli woman was killed. The military also said that Mr. Bitar planned several other suicide attacks that were thwarted, and that he had been arrested by Palestinian forces in September 2008. Mr. Bitar’s wife, Sanaa, said he had been on a hunger strike for 43 days to protest his continued detention without charge or trial. She said that a Palestinian Authority court had ordered his release a while ago. She, too, blamed the Palestinian Authority for Mr. Qawasmeh’s death.

Palestinian officials in the West Bank said such statements only served to remove responsibility from Israel, and suggested that the six had been kept in Palestinian custody for their own safety. Gen. Adnan Damiri, a spokesman for the Palestinian security forces, said that the authority had made it clear before their release that Hamas would have to bear responsibility for protecting them from Israeli forces, according to the official Palestinian news agency, Wafa.

The other recent deaths include the case of a Palestinian woman, 36, who died last Saturday after inhaling tear gas on the sidelines of a protest the day before in the West Bank, according to her family and Palestinian medical officials.

Initially, Israeli military officials anonymously raised questions about whether those accounts were fabricated; Friday brought the first official comment. The army commander in the West Bank, Brig. Gen. Nitzan Alon, was quoted by Haaretz as saying the woman probably died not from tear gas but from other medical “complications, combined with problems in the medical care she received at the Palestinian hospital.”

On Sunday, Israeli soldiers shot and killed a Palestinian man as he approached a checkpoint in the northern West Bank. The military said that he was holding a glass bottle, and that he had approached the checkpoint in an unauthorized lane and failed to heed orders to stop.

© 2011 The New York Times Company