In what American commanders called a crime against the people of Iraq and the country's prime minister called an admission of defeat, officials say ISIS fighters blew up Mosul's most iconic mosque Wednesday night as government troops closed in. The Grand al-Nuri Mosque, more than 800 years old, was where ISIS leader Abu Bakr al-Baghdadi declared a caliphate in 2014 during his only public appearance, the BBC reports. ISIS—whose fighters had been seen bringing explosives to the site, according to CNN—claimed the mosque in Mosul's Old City had been destroyed by American aircraft, but US commanders swiftly denied the claim, saying there had been no strikes in the area.
Aerial photos showed little but rubble remaining at the mosque complex, where the black flag of ISIS had flown since 2014. The destruction of the mosque and its famous minaret "amounts to an official acknowledgement of defeat," Iraqi prime minister Haider al-Abadi said in a statement. The Old City is the only part of Mosul still held by ISIS, and commanders say the "final chapter" of the offensive to retake the city has begun. The Iraqi military says elite counterterrorism units had fought their way to within 170 feet of the mosque, which is at the southern edge of the Old City, when it was destroyed, Reuters reports. (Russia says al-Baghdadi may have been killed in an airstrike last month.)