Russia's Defense Ministry says a general has been killed in fighting in Syria.
The ministry said Sunday that Lt. Gen. Valery Asapov "was at a command post of Syrian troops, assisting the Syrian commanders in the operation for the liberation of the city of Deir al-Zor."
State news agency Tass reported that "as a result of a mortar shelling by the ISIS (Islamic State group), Asapov was mortally wounded."
Asapov, RT reported, was described as one of the senior Russian military advisers in Syria. According to the Russian report, Asapov is the highest-ranking Russian military officer to be killed in Syria.
Asapov was a commander of the 5th Army in Russia’s Eastern Military District, what RT described as one of Russia's four strategic commands, based in Ussuriysk, near Vladivostok.
According to Russian media, at the beginning of the month, two Russian "contract soldiers" were killed by ISIS in Deir al-Zor.
On Saturday, U.S. allied forces seized a major gas field in Deir al-Zor from Islamic State militants in rapid advances that preempted the Syrian government that was also heading in that direction.
In a separate offensive, Syrian army and Iranian backed militias with Russian air power had also this month broke a years-long Islamic State siege of government-held parts of Deir al-Zor on the other side of the Euphrates river.
The advances against Islamic State have brought U.S.-backed forces and the Syrian government side, backed by Russia and Iran, into close proximity.