There were disputed reports on the matter as The New York Times reported the Russian Defence Ministry had claimed Baghdadi had been killed, but other agencies said the matter was still being investigated.
Russian Federation says it may have killed the head of ISIS Ibrahim Abu-Bakr al-Baghdadi and the leadership of the terrorist organisation.
The U.S. -led anti-ISIS military coalition said Friday, however, that it could not confirm the Russian claims.
The Russian army on Friday said it hit Islamic State leaders in an airstrike in Syria last month and was seeking to verify whether ISIS chief Abu Bakr al-Baghdadi had been killed.
There have previously been reports, including in March 2015 and last June, that al-Baghdadi was seriously wounded in air strikes carried out by US-led coalition forces.
There have been numerous claims regarding al-Baghdadi's death before he resurfaces again but Moscow seems confident that he has been finally eliminated.
The Russian Defence Ministry said it bombed a meeting of ISIS or so-called "Islamic State" near the group's city base in Raqqa in Syria. Other state media reported that more than 300 "terrorists" were killed in the strike.
The ministry also noted that the American side was notified in advance through interaction channels about the time and place of the Russian airstrike.
He said all the top leaders of ISIS are thought to be in an area between the Iraqi border and Deir Ezzor, which is about 140km south-east of Raqqa.
The ministry said the IS leaders were gathered to discuss the group's withdrawal from Raqqa, the group's de facto capital.
Al Qaeda leaders later severed relations with him, saying he was insubordinate, killing too many civilians.
It was also gathered that Russian forces are in support of the Syrian government now fighting against IS from the West. A number of senior leaders of the group are believed to have been killed in the strike.
USA and coalition forces have been increasing the pressure in their battle against ISIS in Syria.
This is the first time, however, that Russian Federation has said it may have killed the IS leader.
Baghdadi has not been seen in public since proclaiming himself "caliph" in the Iraqi city of Mosul three years ago.
"His death or capture would be a further body blow to the movement, which has lost much of its territory in Iraq and Syria", said Patrick Cockburn, the award-winning Middle East specialist for The Independent who predicted the rise of Isis before it was well known.