An image grab taken from the video shows Islamist militants destroying priceless statues and sculptures.
New York's famed Metropolitan Museum of Art on Thursday strongly condemned the "catastrophic" destruction of ancient artefacts by extremists in Iraq's second city of Mosul.
Militants from the Islamic State (IS) group knocked statues off their plinths and smashed them to pieces with sledgehammers at a museum in Mosul, all shown on a video released by fighters.
In another scene, a jackhammer is used to deface a large Assyrian winged bull at an archeological site in the city which the Sunni extremist group captured last summer.
"We strongly condemn this act of catastrophic destruction to one of the most important museums in the Middle East," said Metropolitan director Thomas Campbell in a statement.
"This mindless attack on great art, on history, and on human understanding constitutes a tragic assault not only on the Mosul Museum, but on our universal commitment to use art to unite people and promote human understanding.
"Such wanton brutality must stop, before all vestiges of the ancient world are obliterated," he said.
Experts say the items include many pieces from the Assyrian and Parthian eras dating back several centuries before Christ.
The Metropolitan, which was founded in 1870, is one of the largest and wealthiest museums in the world, and last year attracted 6.2 million visitors.