A Russian air strike killed the Islamic State group's spokesman and chief strategist, says Russia's defence ministry.
The ministry says its intelligence confirmed that a Russian air strike on Aleppo province killed 40 IS militants, including spokesman Abu Muhammed al-Adnani.
His death is a major blow to the extremist group, which has been retreating in Syria and Iraq.
The United States said it launched an air strike targeting al-Adnani in the Syrian city of al-Bab, which is north-east of Aleppo.
Pentagon press secretary Peter Cook said on Tuesday the US was "still assessing the results of the strike."
Al-Adnani persistently called for attacks against the West.