Israel has ordered an investigation after soldiers burst into a house and shot dead a Palestinian civilian.
Amr Qawasme, 65, was killed during a pre-dawn operation to re-arrest five members of Hamas who had been released from jail a day earlier.
His widow, Sobheye, described how the soldiers entered the family home in the West Bank town of Hebron and shot her husband dead in his bed.
Western news agency footage of the victim's bed and headboard splattered with blood appeared to corroborate the family's claims.
"I was praying when they entered. I do not know how they opened the door. They put their hand to my mouth and a rifle to my head," Mrs Qawasme told Reuters, adding that she then heard shots from the bedroom.
"I was shocked. They did not allow me to talk. I asked them: 'What did you do?' They asked me to shut up."
The Hamas militant who was the target of the raid apparently lived on the floor below, although the Israeli Defence Forces (IDF) said Mr Qawasme was shot while "present in one of the terrorists' homes".
The shooting is the latest in a spate of deadly incidents involving the Israeli military since the start of the year and will likely raise fears of renewed tension in the West Bank. In a statement, the IDF expressed its regret for the death and promised to present the investigation's conclusions within the week.
Troops later arrested the intended target, Wael Bitar, wanted for allegedly assisting a suicide bomber who killed an Israeli woman in 2008. Some Israeli media reports stated that Mr Bitar was the nephew of the dead man.
Hamas immediately accused the Palestinian Authority (PA), which is dominated by the rival Fatah party, of being complicit with the Israeli authorities in Mr Qawasme's death. The PA had released the five Hamas members from jail a day earlier, following high-level talks between Fatah and Hamas, aimed at reconciling the rival parties. The prisoners, being held on "security" grounds, had not been charged.
The Western-backed PA has arrested hundreds of Hamas members in the West Bank since 2007, prompting fury from Hamas, which holds sway in the Gaza Strip and has engaged in tit-for-tat arrests there. Violence in the West Bank has largely fallen off in recent years.
Mr Qawasme's death brings the number of Palestinians killed by Israeli troops up to five so far this year. Soldiers shot two men they claimed were trying to breach the wall separating Gaza from Israel three days ago and a man was killed at a checkpoint near Nablus after soldiers said he failed to heed orders to halt. And a woman died last week after apparently inhaling tear gas during a demonstration.
*An Israeli soldier was killed last night by friendly fire after an incident where Palestinian militants had reportedly been seen trying to plant explosives along the border fence between Israel and Gaza.