Abu Bakr al-Baghdadi delivering a sermon at a mosque in Iraq during his first public appearance.

:: The destruction of a Mosul mosque where Abu Bakr al-Baghdadi gave his first sermon as an ISIS leader group is an admission of defeat, Iraq’s prime minister said Thursday.

“It’s an official declaration of defeat,” Haider al-Abadi said in a statement issued hours after news that the Nuri mosque, and the iconic “Hadba” leaning minaret next to it, had been blown up on Wednesday.

Iraq’s Ministry of Defense said ISIS destroyed the al-Nuri mosque in Mosul and the iconic leaning minaret when fighters detonated explosives inside the structures late Wednesday night.

The mosque – also known as Mosul’s Great Mosque – is where ISIS leader Abu Bakr al-Baghdadi declared a so-called Islamic caliphate in 2014 shortly after the city was overrun by the militants and was seen as a key symbolic prize in the fight for Iraq’s second largest city.

Iraqi forces launched a push into Mosul’s Old City earlier this week where the last ISIS fighters are holed up with an estimated 100,000 civilians according to the United Nations.

The fight to retake Mosul was launched more than eight months ago and has displaced more than 850,000 people.