A Russian military helicopter was downed in rebel-held Idlib province in Syria on Monday, the Russian defense ministry said. The plane was carrying five people of personnel. It is not clear which group brought the helicopter down.
Russian air forces are supporting President Bashar al-Assad in Syria's five-year-old civil war.
According to the words of the defense ministry, it was an Mi-8 military transport helicopter which had been shot down after delivering humanitarian aid to the city of Aleppo as it made its way back to Russia's main air base in the western province of Latakia.
Two officers and three crew members, who were on the board, had died.
They died a "heroic death" on a humanitarian mission, Kremlin spokesman Dmitry Peskov told a conference call with reporters. He said the helicopter had tried to veer away from inhabited areas to avoid civilian deaths.
Peskov also said that Moscow would continue fighting international terrorism "on all fronts" despite threats from Islamic State.