ISIS leader Abu Bakr al-Baghdadi was reportedly killed in an airstrike on May 28, according to the Russian military.
Russia's Defense Ministry said the air raid targeted an ISIS meeting on the southern outskirts of Raqqa, the Syrian city which serves as the terrorist group's de facto capital in that country, reports the Daily Mail.
Russia began bombing ISIS in Syria in September 2015, in support of Syrian President Bashar al-Assad. Simultaneously, the U.S.-led military coalition in Syria has supported the Syrian rebels who are fighting the Syrian government.
In a statement, the Russian army said: "Senior commanders of the military groups of the so-called IS military council, 30 mid-ranking field commanders and up to 300 militants who provided security for them were eliminated. According to information which is being checked through various channels, the leader of ISIS Ibrahim Abu-Bakr al-Baghdadi was also present at the meeting and was eliminated by the strike."
Al-Baghdadi became the leader of ISIS in 2010 and led it to a series of victories which captured a huge amount of territory, including the cities of Mosul in Iraq and Raqqa in Syria, though it has since suffered major defeats.
At this point, al-Baghdadi's death has not been verified. "We cannot confirm these reports at this time," said U.S. Army Colonel Ryan S. Dillon, spokesman for the coalition.
The ISIS leader's death has been reported more than a dozen times in the past.
"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.
ISIS today "no longer looks anything like the Islamic utopia its founders were claiming to establish and was to serve as a model society for Muslims across the world," Cockburn adds. "The military defeat of ISIS in Mosul, combined with the likely loss of its de facto Syrian capital at Raqqa later this year, means that the movement will no longer control a quasi-state more powerful than many members of the UN."
However, "its demise is by no means so certain," he cautions. "The loss of the two cities means that the self-declared Caliphate will be shrunken and lose much of its population. But prior to its explosive advances in 2014, when it captured much of western Iraq and eastern Syria, it was a skilled and experienced guerrilla movement. Unable to stand against the firepower of an enemy in total control of the air, there are signs that it is moving many of its fighters and officials out of Mosul and Raqqa to rural areas where they can hide more easily."