The Russian Defense Ministry says it has killed four Islamic State (IS) commanders in an air strike targeting the extremist group outside Syria's eastern city of Deir al-Zour, including a former senior security official from Tajikistan.
The ministry said in a September 8 statement that 40 militants were killed in the air strike, including Abu Muhammad al-Shimali, who is responsible for foreign IS fighters, and Gulmurod Halimov, a former Tajik Interior Ministry commander.
It said the air strike targeted a gathering of IS warlords in an underground bunker near Deir al-Zour.
"According to confirmed data, among the killed fighters are four influential field commanders," the ministry said.
Halimov, often referred to as the IS "minister of war," is a former commander of the Tajik Interior Ministry's riot police, known as OMON, who had received U.S. training while serving in that position.
He made an online announcement in May 2015 that he had joined IS.
Tajikistan has issued an international warrant for his arrest, and the United States has offered $3 million for information on his whereabouts.
The Russian Defense Ministry said Halimov was present at the meeting of IS warlords and was fatally wounded in the air strike. It said he had been evacuated to the Al-Muhasan area, 20 kilometers southeast of Deir al-Zour.
There have been several unconfirmed reports from both northern Iraq and Syria since 2015 that Halimov was killed while fighting alongside IS forces.
Tajik authorities have repeatedly rejected those reports, saying they think he is still alive.
Heavy fighting continues between Syrian government forces, backed by Russia, and IS fighters seeking to reinstate a siege of Deir al-Zour.
Russian President Vladimir Putin this week congratulated his Syrian counterpart, Bashar al-Assad, after Syrian state media said government troops had broken the three-year long siege of the city by IS forces.
In the months after Russia began a campaign of air strikes in Syria in September 2015, Western officials said it mainly targeted not IS militants but other opponents of Assad.