Some reports of recent incident says hundreds of Russian mercenaries were killed in Syria last week
Five Russian citizens were likely killed in a US-led coalition bombing of pro-government Syrian fighters last week, Moscow said on Thursday, acknowledging non-military casualties in the attack for the first time.
"We are possibly talking about the deaths of five people, supposedly citizens of the Russian Federation. Others are injured. But this all requires verification, in particular their citizenship. We are not talking about Russian soldiers," said foreign ministry spokeswoman Maria Zakharova.
At the time of the attack in Deir Ezzor last Wednesday, the Russian defence ministry insisted it had no servicemen in the eastern province of Syria.
However, many Russian citizens are fighting in Syria as mercenaries working for a private military company called Wagner, according to numerous reports.
Some media reports said dozens or even hundreds of Russian mercenaries were killed in the attack but Zakharova dismissed these claims as "classic disinformation" spread by anti-government militants.
In a second incident, 15 Russians employed by a private security company were killed when an unexplained explosion rocked an arms depot at their base in the war-torn country, a monitor said on Wednesday.
The incident happened at the company's weapons storage facility at Tabiya Jazira a few days ago in the northeastern province of Deir Ezzor, said the Britain-based Syrian Observatory for Human Rights.
Observatory director Rami Abdel Rahman said the company in question was in charge of "protecting the oil and gas fields controlled by the Syrian regime".
"Fifteen Russians working for a Russian private security company were killed in an explosion at a weapons depot of the company in Tabiya Jazira in Deir Ezzor province," he told AFP.
Seven other people, mostly pro-government Syrian fighters, died in the blast, he added.
Fifteen Russians working for a Russian private security company were killed in an explosion at a weapons depot of the company in Tabiya Jazira in Deir Ezzor province
- Rami Abdel Rahman, SOHR director
The Russian workers had been at the site when "regime forces were trying to take the Coneco gas field" controlled by the Syrian Democratic Forces (SDF), a US-backed alliance of Arab and Kurdish fighters.
Their reported deaths come after the US-led coalition struck the Coneco plant last Wednesday in retaliation for an attack on an SDF base near the gas field on the eastern bank of the Euphrates river.
The US-led coalition said it killed at least 100 pro-government fighters to fend off an attack on its allies in eastern Syria, in one its deadliest confrontations yet with forces backing Damascus.
At least six Russian mercenaries - and reportedly scores more - who were fighting on the side of Bashar al-Assad, died in the US strikes, multiple reports from Russia suggest.
The Observatory, which relies on a network of sources on the ground in Syria, said 45 pro-government fighters were killed.
The Assad government denounced the strikes as a "war crime".
The US-led coalition was established in 2014 to fight the Islamic State group in Syria and Iraq, but it has bombed troops loyal to Damascus on several occasions.