Russia claimed on Friday its airstrikes killed four top ISIS commanders in Syria, including the group's "minister of war" and the "Emir of Deir ez-Zour".
"As a result of a precision airstrike of the Russian air forces in the vicinity of Deir ez-Zour city, a command post, communication centre and some 40 [IS] fighters have been killed," the Russian defence ministry said in a statement on Facebook.
"According to confirmed data, among the killed fighters are four influential field commanders including Deir ez-Zour emir Abu Mohammed al-Shimali," the ministry said.
Gulmurod Khalimov, a native of Tajikistan who is known as the group's "Minister of War", suffered a "fatal injury", the ministry added.
Khalimov headed the Tajik interior ministry's Special Forces unit before joining IS in 2015.
Heavy clashes continued between Syrian regime forces - backed by Russia - and IS militants fighting to reinstate a three-year-long siege imposed on tens of thousands of civilians in Deir ez-Zour.
Syrian regime forces broke the siege on Tuesday, marking a significant advance against the militants.
