The three-minute video posted on Thursday seems to have captured part of a raid that the Egyptian army highlighted in a Facebook post on December 6, 2016. That post included photos of three lifeless, bloodied bodies in a grassy area with rifles next to them. The post said they had been killed in a military raid on a terrorist base and an explosives storehouse.
The new footage purportedly shows the summary execution of at least three people.
In one case, a soldier casually holds a rifle over a man on the ground and shoots him in the head. In another, soldiers escort a blindfolded man into the field, place him on his knees, and shoot him several times in the head and upper body.
There is speculation that the summary executions were staged by the soldiers to look as if the deaths had happened in combat.
Hundreds of security forces have been killed in violent clashes with or bombing attacks by militants across the Sinai Peninsula over the past months. The troubled region has been under a state of emergency since October 2014, following a deadly terrorist attack that left 33 Egyptian soldiers dead.
The Takfiri Velayat Sinai terrorist group, which is linked to Daesh, has been responsible for most of the attacks in the Sinai Peninsula.
Militants have carried out numerous terrorist attacks in Sinai and elsewhere in Egypt in the past years, taking advantage of the turmoil that was caused after the 2013 ouster of the democratically-elected President Mohamed Morsi by the army.