A Russian helicopter crashed in Syria late on Monday killing both pilots, Moscow's defence ministry said in a statement carried by news agencies.
"A Russian Ka-52 helicopter crashed while on a routine flight over the eastern regions of the Syrian Arab Republic. Both pilots were killed," the statement said, quoted by the TASS news agency.
It added that the incident "may have been due to a technical malfunction" and that a rescue team recovered the bodies.
The incident is the Russian army's second deadly crash in Syria in less than a week. On May 3, a Russian fighter jet crashed after taking off from an airbase, killing both pilots.
Monday's accident brings Russia's official military losses in Syria to 88.
Russian nationals are also regularly reported to be serving as paid mercenaries in Syria, and sometimes killed.
The most recent large military loss acknowledged by Russia came when a transport plane crashed on landing at the Hmeimim airbase in March, killing all 39 people on board.