IS video said to show killing of Egyptian Christians

Islamic State militants have released a video said to show the mass execution of Egyptian Christians who had been kidnapped by Libyan militants allied to the group.

The footage shows a group wearing orange overalls, being forced to the ground, and then decapitated.

Egypt's President Abdul Fattah al-Sisi has called for an urgent meeting of Egypt's National Defence Council to decide how to respond.

The BBC's Orla Guerin reports from Cairo.