The Kremlin has confirmed that Russian military personnel on board a helicopter shot down in Syria are dead, citing the Russian Defence Ministry.
The helicopter, with five people on board, was shot down in Idlib Province, Russian news agencies quoted the Defence Ministry as saying.
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.
On Sunday, Islamic State posted a nine-minute video message on YouTube, calling on its members to carry out jihad or holy war in Russia.