Palestinian security sources said Omar Salim Al-Qawasmi, 65, was killed while sleeping in his bed when the Israeli forces raided a building to arrest Hamas member Wael Al-Beitar.

Palestinian doctors in the Hebron government hospital said that Al-Qawasmi had bullet wounds to the upper part of his body.

Raja'I Al-Qawasmi, the dead man's son, said: "The soldiers entered our house when my mother was praying. They put her in my disabled brother's room, entered my father's bedroom and shot him. They left the house after arresting Al-Beitar, who lives on the first floor of our building."

He said the Israeli soldiers "took the body with them, which they later handed over to the Palestinian Red Crescent."

Al-Beitar and five other Hamas members — Majdi Obeid, Ahmed Al-Qawasmi, Mohanned Nairoukh, Wisam Al-Qawasmi and Mohammed Soqiyeh — were arrested during the Israeli raid.

The Israeli Army said the six were involved in attacks against Jewish occupiers and other Israeli targets, particularly in an August 2010 shooting in which four occupiers were killed on a road leading to a settlement near Hebron.

Palestinian President Mahmoud Abbas ordered their release on Thursday after Hamas strongly criticized the Palestinian Authority for keeping them in prison.

The Israeli Army expressed its regret over the killing of Omar Salim Al-Qawasmi. It said in a statement that Maj. Gen. Avi Mizrahi, Central Command chief, had ordered an investigation into the incident.

Ahmed Tibi, Knesset member of the United Arab List party, called it a "cold-blooded murder of an elderly man." Tibi demanded trial of those involved in the killing to make it clear that Palestinian blood cannot be spilled without consequences.

Speaking on behalf of the Palestinian Authority, chief Palestinian negotiator Saeb Erekat said: "We condemn the Israeli actions in Hebron today."

Hamas demanded that the Palestinian Authority stop the security coordination with Israel.

Sami Abu Zuhri, Hamas spokesman in Gaza, said on Friday that the Israeli raid and the arrest of Hamas members was "a dangerous Israeli escalation." He said the Palestinian Authority should release all Hamas prisoners held in West Bank prisons.