A senior Lebanese security official says that the military has received the remains of a soldier who was held by Islamic militants and believed decapitated.

The official said they received the remains of Sgt. Ali Sayid on Monday.

It came days after supporters of the extremist Islamic State group distributed a video showing a man they identified as Sayid being decapitated.

The security official wouldn't say how the man was killed or whether he was beheaded. He spoke on condition of anonymity, citing military guidelines.

Sayid disappeared from Lebanon around the time militants from Syria attacked the Lebanese border town of Arsal in early August, killing and kidnapping soldiers and police. It was the most serious spillover of violence into Lebanon from Syria's civil war.