The Russian defence ministry says it believes it may have killed the Isis leader Abu Bakr Al-Baghdadi in an air strike south of Raqqa, Syria. In a statement, the ministry said it was still seeking confirmation following the strike in late May.

The air strike targeted a meeting of Isis leaders on 28 May, Russian news agencies cited the defence ministry as saying.

"According to the information which is now being checked via various channels, Islamic State leader Abu Bakr al-Baghdadi, who was eliminated by the air strike, was also present at the meeting," RIA news agency quoted the ministry as saying.

The statement claimed the 28 May strike killed around 30 mid-level Isis leaders and another 300 fighter, during a meeting of Isis's "military council" on the southern outskirts of Raqqa. The jihadi group's de-facto capital is surrounded to the north, east and west by advancing Syrian rebel and Kurdish forces backed by the US-led coalition.

Russia said multiple Su-24 and Su-25 aircraft were involved in the strike, acting upon intelligence captured by drone footage. It said it had informed the US in advance of the strike.

Baghdadi rose to international prominence when he declared the territories occupied by the Isis militancy a so-called "caliphate" during a rare public appearance in Mosul in the summer of 2014.

There have been multiple previous unverified reports of his death. In mid-June, a doctored online statement purporting to be from Isis's Amaq news agency claimed Baghdadi had been killed in a US air strike.

In March, the US Secretary of State Rex Tillerson said "nearly all" Baghdadi's deputies had been killed as Isis's territory was squeezed in both Syria and Iraq. He said it was "only a matter of time before Baghdadi himself meets this same fate".