MOSCOW, Aug 31 (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, on Tuesday.

The ministry said that Adnani was one of up to 40 rebels killed by the air strikes in Syria's region of Maaratat-Umm Khaush, in the Aleppo province.

On Tuesday, a U.S. defence official told Reuters the United States targeted Adnani in a strike.

(Reporting by Lidia Kelly; Editing by Dmitry Solovyov) ((lidia.kelly@thomsonreuters.com; +7 495 775 1242; Reuters Messaging: lidia.kelly.reuters.com@reuters.net))