Iconic Mosul mosque where IS leader declared caliphate 'destroyed'

Mosul's iconic leaning minaret and the adjacent mosque where Islamic State leader Abu Bakr al-Baghdadi declared a "caliphate", was blown up on Wednesday, reports confirmed, despite conflicting claims surrounding the exploson.

The Nuri and Hadba mosques, the city's two best known landmarks and the sites from which al-Baghdadi made his first and only public appearance in 2014, were destroyed as Iraqi forces delved deeper into the Old City, an Iraqi commander confirmed, blaming the destruction on IS militants.

"Our forces were advancing toward their targets deep in the Old City and when they got to within 50 metres (yards) of the Nuri mosque, Daesh (IS) committed another historical crime by blowing up the Nuri mosque and the Hadba" mosque, Staff Lieutenant General Abdulamir Yarallah, the overall commander of the Mosul offensive, said in a statement.

But the Islamic State group, which is usually quick to claim responsibility for varying attacks across the world, swiftly issued a statement via its Amaq propaganda agency refuting the claims and blaming it instead on a US strike.

It adds to a long list of Iraqi heritage sites and monuments destroyed in both Iraq and Syria, since al-Baghdadi declared the so-called caliphate almost exactly three years ago.

IS proclaimed its self-styled "caliphate" in June 2014, after sweeping across Iraq's Sunni Arab heartland, an unprecedented experiment in jihadist statehood.

The Iraq-born al-Baghdadi appeared at the Nuri mosque in Mosul, Iraq's second city, days later to declare himself "caliph" and urge the world's Muslims to move in.

It remains the last public appearance to date for the militant supremo, whose fate and whereabouts are currently unclear and whose "state" has been shrinking for two years.

When IS imposed its tyrannic brand of sharia, or Islamic law, in the early stages of its "caliphate", it destroyed several key heritage sites in Mosul, including the main museum and shrines to Jonah and Seth.

It reportedly rigged the "Hadba", which it sees as the subject of a cult that transgresses its own regressive and ultra-conservative brand of Islam, but was prevented from blowing it up by the local population.

The news comes on the fourth day of an Iraqi offensive, backed by the US-led coalition, on the Old City, where holdout IS militants are making a bloody last stand.