BAGHDAD/Doha - The leader of the Islamic State jihadist group, Abu Bakr al-Baghdadi, purportedly ordered all Muslims to obey him in a video released Saturday on social media.

The hitherto elusive Baghdadi, who on June 29 proclaimed a ‘caliphate’ straddling Syria and Iraq, made his appeal in a sermon delivered on Friday in the militant-held northern Iraqi city of Mosul. ‘I am the wali (leader) who presides over you, though I am not the best of you, so if you see that I am right, assist me,’ he said, wearing a black turban and robe.

‘If you see that I am wrong, advise me and put me on the right track, and obey me as long as I obey God in you.’ AFP was not immediately able to confirm the authenticity of the video purportedly showing Baghdadi, of whom there were previously only two known photographs.

 ‘This is a duty on Muslims that has been lost for centuries,’ he added, sporting a long and slightly greying beard, as he addressed the faithful from the mosque’s pulpit.

The Iraqi government said on Saturday that a video posted online purporting to show the reclusive leader of the militant group Islamic State praying in the northern city of Mosul was falsified.

Interior Ministry spokesman Brigadier General Saad Maan told Reuters that the footage posted on the Internet on Saturday allegedly showing Abu Bakr el-Baghdadi at Mosul’s grand mosque was ‘indisputably’ not him. ‘We have analysed the footage and found it is a farce,’ he said.

Maan said government forces had recently wounded Baghdadi in an air strike and that he had been transferred by Islamic State militants to Syria for medical treatment. He declined to give further details and there was no way to confirm the claim independently. The 21-minute video came after reports on social media that Baghdadi would make his first public appearance since his Islamic State in Iraq and the Levant (ISIL) changed its name to the Islamic State and declared him caliph - a title held by successors of the Prophet Mohammad.

Mosul, northern Iraq’s biggest city, was overrun on June 10 early in an offensive that saw vast parts of Iraq’s majority Sunni regions fall to the Islamic State and allied groups. The Iraqi government has in the past made claims to have captured wanted Sunni militants only to announce later that the men were still at large.

Since last Sunday, other leading Muslim figures have denounced the announcement by the Islamic State, which was previously known as the Islamic State of Iraq and the Levant. A caliphate is fundamentally a universal Islamic state ruled by a single leader with both political and religious authority. Iraq’s most senior Christian leader appealed Saturday for the release of two nuns and three orphans who have been missing for several days in militant-held areas of northern Nineveh province.

The group went missing on Tuesday in Mosul, the first city to fall in a major militant offensive last month that overran swathes of territory across five provinces north and west of Baghdad, and have not been seen since. ‘We are appealing for scholars in Mosul and tribal sheikhs to help us release two nuns and three orphans,’ said Chaldean Patriarch Louis Sako. Jihadists who overran Mosul last month have demolished ancient shrines and mosques in and around the historic northern Iraqi city, residents and social media posts said Saturday. At least four shrines to Sunni Arab or Sufi figures have been demolished.

, while six Shiite mosques, or husseiniyahs, have also been destroyed, across militant-held parts of northern Nineveh province, of which Mosul is the capital.

Pictures posted on the Internet by the Islamic State (IS) jihadist group showed the Sunni and Sufi shrines were demolished by bulldozers, while the Shiite mosques and shrines were all destroyed by explosives. The photographs were part of an online statement titled ‘Demolishing shrines and idols in the state of Nineveh.’

Local residents confirmed that the buildings had been destroyed and that militants had occupied two cathedrals as well. ‘We feel very sad for the demolition of these shrines, which we inherited from our fathers and grandfathers,’ said Ahmed, a 51-year-old resident of Mosul. ‘They are landmarks in the city.’

An employee at Mosul’s Chaldean cathedral said militants had occupied both it and the Syrian Orthodox cathedral in the city after finding them empty. They removed the crosses at the front of the buildings and replaced them with the Islamic State’s black flag, the employee said. IS-led militants overran Mosul last month and swiftly took control of much of the rest of Nineveh, as well as parts of four other provinces north and west of Baghdad, in an offensive that has displaced hundreds of thousands and alarmed the international community.