28 August 2014 :

a Sinai-based militant group said it had beheaded four Egyptians, accusing them of providing Israel with intelligence for an airstrike that killed three of its fighters.
Four headless corpses were found in the Sinai Peninsula in early August, security sources said - the first time that any decapitations had been made public in Egypt.
In a video released on Twitter, Egypt’s most dangerous militant group, Ansar Bayt al-Maqdis, said the four men had been spying for Israel’s Mossad spy agency.
Armed men in black masks stood over the kneeling captives as one of the militants read out a statement. Minutes later, the four men had their heads cuts off.
In the video, Ansar Bayt al-Maqdis presented what it said were confessions by the men. Two of them said they had spent time in Israeli jails for smuggling. The other two said Mossad had paid them for information.
The group said the men provided intelligence used in an airstrike on 23 July in northern Sinai that killed three of its fighters. At the time, the Egyptian army said no Israeli aircraft or drones had crossed into Egyptian airspace.
Militants in the Sinai have stepped up attacks on policemen and soldiers since then-army chief Abdel Fattah al-Sisi toppled President Mohamed Mursi of the Muslim Brotherhood in July 2013.