A video was published on a social media website purporting to show Islamic State militants destroying the ancient Assyrian City of Nimrud in Iraq.

Reuters reported on March 6 that Islamic State fighters had looted Nimrud in one of their several assaults on some of the world's greatest archaeological and cultural treasures.

The video showed IS militants using sledgehammers, electric drills and an electric saw to destroy the artefacts before blowing up one site with a large amount of explosives.

Reuters is unable to independently verify the content of this video, which has been obtained from a social media website.

A tribal source from the nearby city of Mosul told Reuters in March that the radical Sunni Islamists, who dismiss Iraq's pre-Islamic heritage as idolatrous, had pillaged the 3,000-year-old site on the banks of the Tigris River.

The assault against Nimrud came just a week after the release of a video showing Islamic State forces smashing museum statues and carvings in Mosul, the city they seized along with much of northern Iraq last June.

Nimrud, about 30 km south of Mosul, was built around 1250BC. Four centuries later it became capital of the neo-Assyrian empire - at the time the most powerful state on Earth, extending to modern-day Egypt, Turkey and Iran.

Many of its most famous surviving monuments were removed years ago by archaeologists, including colossal Winged Bulls which are now in London's British Museum and hundreds of precious stones and pieces of gold which were moved to Baghdad.

But ruins of the ancient city remain at the northern Iraqi site, which has been excavated by a series of experts since the 19th century. British archaeologist Max Mallowan and his wife, crime writer Agatha Christie, worked at Nimrud in the 1950s.

Islamic State, which rules a self-declared caliphate in parts of Iraq and Syria, promotes a fiercely purist interpretation of Sunni Islam which seeks its inspiration from early Islamic history.

It rejects religious shrines of any sort and condemns Iraq's majority Shi'ite Muslims as heretics.