MOSCOW (Reuters) - Russia's Defence Ministry said on Wednesday that Russian air strikes in Syria had killed one of Islamic State's most prominent leaders, Abu Muhammad al-Adnani.

The ministry said that Adnani was one of up to 40 rebels killed on Tuesday by air strikes carried out by a Russian Su-34 bomber in Maaratat-Umm Khaush in Aleppo province.

Islamic State said on Tuesday Adnani had been killed in what appeared to be an U.S. air strike in Syria. A U.S. defence official told Reuters the United States targeted Adnani in a strike but stopped short of confirming his death.

Russia's Defence Ministry said Adnani's killing by the Russian air strike had been confirmed "through several intelligence channels".

Islamic State's Amaq News Agency reported on Tuesday that Adnani was killed "while surveying the operations to repel the military campaigns against Aleppo".

(Reporting by Lidia Kelly; Editing by Dmitry Solovyov; Editing by Louise Ireland)