Col. Gen. Sergei Rudskoi said Russian jets are now making 60 to 70 flights a day to target militants heading from other areas to join the fight in the eastern city. He says Syrian troops were, meanwhile, advancing from three directions to encircle Deir El-Zour.
The Syrian regime controls around half the city and a nearby air base, both of which are besieged by the militants. Rudskoi said militants fleeing US-backed offensives in the Iraqi city of Mosul and the Syrian city of Raqqa have poured into Deir El-Zour in recent months.
He said Syrian troops have also encircled Akerbat, a Daesh-held town in central Syria, and that Russian warplanes have targeted militant convoys trying to flee the area for Deir El-Zour.
Russia has waged an air campaign in Syria since September 2015 aimed at helping Assad’s forces defeat Daesh as well as Syrian rebel groups.
This month alone, Russian warplanes have flown 990 missions, destroying 40 armored vehicles, more than 100 trucks and killing about 800 militants, Rudskoi said.
Those casualties include more than 200 militants killed in a recent raid on a Daesh convoy heading toward Deir El-Zour, according to the Russian Defense Ministry.
Rudskoi said the creation of de-escalation zones in Syria has helped the Russian military to focus on battling Daesh.
Under a plan approved in May by Russia, Turkey and Iran that applies to three areas of the country, the regime and Syrian opposition have agreed to cease hostilities, halt government air raids and improve humanitarian access. Russian military police are monitoring compliance at checkpoints around the three zones.
The Syrian Observatory for Human Rights monitor US-led coalition strikes on Sunday killed 27 civilians in part of Raqqa city held by Daesh.
Seven children were among the dead in the strikes that “hit the densely-populated Al-Badu area in the center of the city,” said Rami Abdel Rahman, Observatory director.
Once a terrorist stronghold, more than half of Raqqa city has fallen to the Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab fighters that entered the city in June.
The SDF is heavily backed by the US-led coalition, which has regularly launched airstrikes against the terrorists.
The Britain-based Observatory said at least 125 civilians had been killed in a week of US-led strikes on Raqqa city, including those who died on Sunday.
“There are civilians killed each day in coalition strikes... The closer the fighting gets to the densely-populated city center, the more civilian deaths there are,” Abdel Rahman said.
The coalition, which operates in both Syria and Iraq, says it takes all possible measures to avoid civilian casualties.
In August, it acknowledged the deaths of 624 civilians in its strikes in Syria and Iraq since 2014, but rights groups say the number is much higher.
The UN’s humanitarian pointman for Syria, Jan Egeland, has said Daesh-held territory in Raqqa city is now “the worst place” in the country.
The UN estimates there are up to 25,000 civilians trapped inside the city, with food and fuel supplies short and prohibitively expensive.
Tens of thousands of civilians have also fled the city, risking Daesh sniper fire and land mines in the process.