UPDATE: 6: 27 a.m. EDT — Just hours after a spokesman for the U.S.-led anti-Islamic State coalition said he cannot confirm reports that Abu Bakr al-Baghdadi has been killed in Syria, Russian Foreign Minister Sergey Lavrov said he cannot definitively Russian airstrike killed the ISIS leader.

 “I don’t have a 100-percent confirmation of the information,” Lavrov said adding, “past examples of similar actions to strike the leadership of terrorist groups were presented with much enthusiasm and pomp, but the experience shows that those structures later regained their capability.”

UPDATE: 4:00 a.m. EDT — Nearly 30 Islamic State group (ISIS) commanders and up to 300 fighters were at the meeting in Raqqa when Russia-backed airstrikes hit the area on May 28, Russia's defense ministry said in a statement Friday. The ministry believes Abu Bakr al-Baghdadi and up to 330 other fighters were killed. A Russian Su-34 aircraft and a Su-35 multirole reportedly carried out the strikes.

“We informed the American side in advance of the raid that is likely to have killed Baghdadi,” the ministry said. The Department of State has designated Baghdadi as a Specially Designated Global Terrorist (SDGT).

Here are some Twitter reactions to news of Baghdadi's killing:

 

Original story:

A Russia-backed airstrike may have killed Islamic State group's (ISIS) leader Abu Bakr al-Baghdadi, reports said early Friday, adding that Moscow was investigating the claims. Over the years, several reports claiming to have captured, wounded or killed Baghdadi have surfaced, ultimately proving to be untrue.

Russia's Defence Ministry said the airstrike near the Syrian city of Raqqa on May 28, targeted a meeting of ISIS leaders. "According to the information which is now being checked by various channels, Baghdadi, who was eliminated by the air strike, was also present during the meeting," RIA news agency quoted the ministry as saying.

Earlier this year, reports claimed Iraqi warplanes struck a house where Baghdadi was reportedly meeting some of the militant organization's top commanders. "Iraqi intelligence was carefully monitoring the movements of Baghdadi, but his injury has not yet been confirmed," an Iraqi defense spokesperson was quoted as saying Monday to Palestinian news outlet Dunya al-Watan.

Baghdadi, whose real name is Ibrahim al-Samarrai, is responsible for turning ISIS into a formidable force in northern Iraq and parts of Syria after helping the group splinter off from al Qaeda. Baghdadi is believed to be 45 years old and from Samarra, located north of Baghdad.

This is a developing story.