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.

Sergei Lavrov, the Russian foreign minister, said Russia has not yet confirmed the death of Baghdadi, and warned against exaggerating the significance of his possible demise. He said the "beheading of terrorist groups has always been presented with great enthusiasm, however, history shows that the fighting capacity of these structures [terror groups] were then restored" afterwards.

Kremlin spokesman Dmitry Petrov declined to comment on the reports, saying only that that Russian President Vladimir Putin received reports from the ministry on a regular basis.

And the US-led coalition said it was unable to verify that Baghdadi had been killed.

The statement from the Russian defence ministry claimed the 28 May strike killed around 30 mid-level Isis leaders and another 300 fighters, 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.

In pictures: Isis' weapons factories Show all 11 1 /11 In pictures: Isis' weapons factories In pictures: Isis' weapons factories A mortar round fin manufactured by Isis in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis rocket components discovered in Gogjali, Mosul, Iraq in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortars discovered near Karamlais, Iraq, in November 2016 CAR In pictures: Isis' weapons factories An Isis rocket launch frame in Qaraqosh, November 2016 Conflict Armament Research In pictures: Isis' weapons factories A memo from Isis' COSQC on quality control at a manufacturing facility in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Electrically-operated initiators manufactured by Isis in forces Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortar tubes at a manufacturing facility in Karamlais, November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis mortar production facility discovered in Gogjali, Mosul, in November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis weapons manufacturing facilities near Mosul in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Stocks of French-manufactured Sorbitol, Latvian potassium nitrate and Lebanese sugar at an Isis weapons factory in Iraq Conflict Armament Research In pictures: Isis' weapons factories A destroyed Isis weapons facility in Qaraqosh, Iraq, November 2016 Conflict Armament Research

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.