A senior Hamas leader has been killed in an explosion at his home in a Gaza Strip refugee camp.
Witnesses said they saw Israeli helicopters over Bureij refugee camp shortly after the blast killed the militant, identified by Hamas officials as Abdel Naser Abu Shuka, 36.
None of the witnesses saw any missiles being fired at the militant's home, but Hamas activists used local mosque loudspeakers to accuse Israel of assassinating him.
The Israeli army denied the military was involved in the incident.
Palestinian security officials said they were investigating whether Abu Shuka, the local leader of Hamas, was killed by a booby-trapped package or by an explosive detonating accidentally in his hands.
The incident occurred shortly after an Israeli army officer was shot and wounded during a raid aimed at arresting a member of another militant group, Islamic Jihad, in the West Bank.
Soldiers blew up a house during the raid in the West Bank village of Burkin where the militant was believed to be hiding, but initial reports said no one was in the building at the time.