Four Russian military personnel have been killed and three Russian soldiers injured during a clash with militants in Deir el-Zour, according to the Russian Defense Ministry on Sunday.
"An artillery battery of the regime's forces was attacked this night; two Russian military advisers, who controlled the fire of the Syrian battery, were killed on the spot," the ministry said in an earlier statement.
Russian servicemen along with the Syrian regime forces together fought the militants during the clash that lasted for about an hour; "43 terrorists" were also killed and six vehicles with heavy weapons were also destroyed, the statement added.
Five Russian soldiers were also injured and were promptly taken to the Russian military hospital, it said. Out of the five injured, two later succumbed to their wounds at a hospital, raising the death toll to four, another statement later said.
Syria, which has been locked in a devastating civil war since early 2011, when the Bashar al-Assad regime cracked down on pro-democracy protests with unexpected ferocity.
According to UN estimates, hundreds of thousands of people have been killed in the conflict.
