Violence in Sinai has increased since the military toppled President Mohammed Morsi on July 3 following demonstrations by millions calling for him to leave office. Several al-Qaida-inspired militant groups have stepped up attacks on security and military targets in the peninsula. The Egyptian military has responded with intensified operations to eliminate the militants and their sanctuaries in the lawless desert area.
Meanwhile, Egypt's prosecutor general ordered the detention of four policemen on the basis of accusations related to the August deaths of more than 30 detainees held in a prison truck, a security official said. The police were accused of committing manslaughter by firing tear gas into the trucks.
The incident happened after police cracked down on pro-Morsi protest camps in Cairo, killing hundreds. The prisoners were mostly supporters of the ousted president.
Many policemen have been referred to trial over allegations of killing protesters and other abuses since the 2011 overthrow of authoritarian leader Hosni Mubarak, but convictions remain rare.
The official spoke anonymously as he was not authorized to talk to media.