Militants with the self-proclaimed Islamic State have reportedly bulldozed the ancient Assyrian city of Nimrud, in northern Iraq, in what the head of UNESCO has called a “war crime.” The ancient site was founded in the 13th century B.C. Its reported destruction comes a week after video showed ISIS militants smashing priceless statues at the Mosul museum, northwest of Nimrud. Further south, meanwhile, Iraqi forces and Iranian-backed militias are continuing their bid to retake the city of Tikrit from ISIS. The militants have set oil wells ablaze northwest of the city in a bid to slow the offensive.