A video allegedly showing Islamic State militants using bulldozers and explosives to destroy the ancient Assyrian city of Nimrud has been posted online.

The UNESCO cultural site near Mosul is one of Iraqi's greatest archaeological treasures.

The seven-minute video shows the jihadists vandalizing the ancient reliefs in Nimrud, an area that is held by militants.

They also used sledgehammers and drills to bring down some of the walls and ultimately levelled the whole complex with explosives.

The video follows a statement made by Iraq's Ministry of Tourism and Antiquities in March. It said Nimrud, a UNESCO cultural heritage site with archaeological riches dating back to the 13th century BC, was bulldozed with heavy machinery.

Image: A video grab of the city being destroyed.