Roughly 40 U.S. commandos held off about 500 forces loyal to the Syrian government - including Russian mercenaries - in an intense firefight in early February, The New York Times reports.
The Russian statement raised the official count of soldiers killed in Syria to 92.
Russian fighters were among dozens of pro-government forces killed in eastern Syria this week in a deadly wave of attacks by Islamic State group jihadists, Moscow and a monitor said Sunday.
Through surveillance of radio transmissions, the U.S. discovered that at least some of the pro-government forces were speaking Russian, stoking the fears, according to The Times. It says 26 Syrian forces were also killed. The military ministry noted that Syrian soldiers, along with the Russian military advisors attached to them, had accepted the battle.
It added five other Russian soldiers were wounded during the incident which took place when "several mobile terrorist groups attacked Syrian government artillery at night". During the battle with terrorists, which lasted about one hour, servicement eliminated 43 terrorists and six all-terrain vehicle with installed large caliber weapons.
Initially, two Russian military advisers died.
Despite various statements by Putin's government suggesting that the Russian military had completed its role in the area, it has become an essential pillar for the government of President Bashar al-Assad of Syria.
"The command of all the Russian military presented to the state awards", - stated in the defense Ministry.
It said two more Russian soldiers died later in a Russian military hospital following the fighting.
All this could bring Russian Federation and the U.S. to the bloody conflict but pro-Syrian government lost the battle.
"The latest attack brings to 76 the number of Syrian troops and allied Iranian and Russian forces killed since the escalation", Abdel Rahman said Sunday.