BAGHDAD, Iraq (CNN) -

Iraqi authorities are looking at a video that purportedly shows Abu Bakr al-Baghdadi delivering a sermon in Mosul to determine whether it is really the notorious leader of the Islamic State of Iraq and Syria, Iraq's military spokesman said Sunday.

The video surfaced on social media sites tied to ISIS, the terror group that now calls itself the Islamic State. It shows a man identified as al-Baghdadi conducting Friday prayers at the Great Mosque of al-Nuri.

"The video is being analyzed and cross-referenced with intelligence data to determine whether it is in fact al-Baghdadi," said Qassim Atta, the military spokesman.

The United States government is also examining the video. If it is al-Baghdadi, it would be one of the first known appearances of the elusive extremist militant leader to be captured on video. Very few images have been made public of al-Baghdadi.

ISIS fighters took control of Mosul, Iraq's second largest city, in early June following a quick campaign that saw Iraqi security forces quickly fold under their assault.

The release of the video comes days after unconfirmed reports surfaced that the militant leader had either been killed or wounded in airstrikes in Iraq's western Anbar province or in the Mosul area.

The timing of the video also appears to coincide with a declaration by ISIS last week of the creation of an Islamic state that stretches from the northeast city of Aleppo in Syria to Iraq's Diyala province.

As part of that declaration, an ISIS spokesman said the group would now be known as the Islamic State, and al-Baghdadi as its leader would be known as Al-Khalifah Ibrahim -- a reference to the leading religious figure considered a successor to the Prophet Mohammed.

The video, which was released by the media arm of ISIS, identified the man as Al-Khalifah Ibrahim.

CNN cannot independently verify the authenticity of the video, which shows dozens of people, including men who appear to be bodyguards, listening to the sermon and praying. Several automatic weapons are displayed near the man delivering the sermon.

In the video, the man purported to be al-Baghdadi urges people to follow his call to create an Islamic state in Iraq and Syria and wage jihad, or holy war, during Ramadan -- the holy month of fasting for Muslims that began at the end of June.

"It is a month from Allah when we are protected from hell, and this is every night -- nights during which the marketplace of jihad is open," he said, according to a translation of the video posted by SITE Intelligence Group, which monitors terror groups.

Very little is known about al-Baghdadi, a name he appears to have adopted just before taking the reins of al Qaeda in Iraq, a group that later reformed under the banner of ISIS.

A biography posted on militant websites last year said he earned a doctorate in Islamic studies from the University of Baghdad.

A man named Al-Baghdadi was detained for four years in Camp Bucca, which was a U.S.-run prison in southern Iraq. He was released in 2009. CNN cannot confirm whether it is the same man.