Relief of a lamassu (human-headed winged lion) in Palace of Ashurnasirpal II, 870 BC, Nimrud, Iraq. Sumerian civilisation, 9th century BC. DeAgostini/Getty Images

The Islamic State group destroyed the archaeological site of the ancient Assyrian city of Nimrud in northern Iraq, several media reports said Thursday, citing the Iraqi Ministry of Tourism and Antiquities. The attack comes one week after a video showed ISIS militants smashing statues and other priceless cultural treasures with sledgehammers in the Mosul Museum.

Members of the terror group, formerly known as ISIS or ISIL, “assaulted the historic city of Nimrud and bulldozed it with heavy vehicles” shortly after noon prayers on Thursday, the tourism and antiquities ministry said on an official Facebook page. “Until now, we do not know to what extent it was destroyed,” an anonymous Iraqi antiquities official told Agence France-Presse, adding that trucks spotted at the site may have been used to haul away centuries-old artifacts.

An Iraqi official told Al Jazeera the large winged statues -- placed at the gates of the place of Assyrian king Ashurnasirpal II -- were among the ancient artifacts smashed at Nimrud. These Assyrian protective deities known as Iamassu are often depicted with the body of a lion or bull, eagle's wings and a human's head.

“Today, terrorism destroyed the city of Nimrud,” the Iraq Museum in Baghdad said on its Facebook page Thursday, urging the world to protect what’s left of these ancient civilizations.

Nimrud, originally called Kalhu, was built in the 13 century B.C. during the Middle Assyrian Empire. The ancient Assyrian city sits on the river Tigris in northern Mesopotamia some 19 miles south of ISIS-controlled Mosul in Iraq.

“It is important to note that this part of the world -- the Euphrates and Tigris River valleys -- holds a record of the earliest development of states and urban economies, which was around 4000 B.C.,” said University of Michigan professor of anthropology Henry Wright, whose most recent field study in Syria was overtaken by ISIS militants.

ISIS has declared their intention to destroy pre-Islamic artifacts that offend its religion. The Sunni militants were videotaped destroying 3,000-year-old stone sculptures at Mosul Museum just last week. "These ruins that are behind me, they are idols and statues that people in the past used to worship instead of Allah," one ISIS militant said in the video. "The Prophet Muhammed took down idols with his bare hands when he went into Mecca. We were ordered by our prophet to take down idols and destroy them, and the companions of the prophet did this after this time, when they conquered countries.”

The United Nations last month banned all trade in looted antiquities from Iraq and Syria in an effort to target sources of financing for the Islamic State group. In addition to destroying some artifacts, ISIS militants have pillaged archaeological sites and sold their loot to collectors around the world to help fund their insurgency operations.