A Russian Mi-8 helicopter was shot down in Syria on Monday, killing all five people on board, Russian President Vladimir Putin's spokesman said.
"They died heroically," spokesman Dmitry Peskov told state news agency TASS. "The Kremlin sends its profound condolences to the loved ones of our deceased servicemen."
The helicopter, carrying three crew members and two officers from Russia's centre for reconciliation of the Syrian conflict, was shot down in Syria's north-western Idlib province, the Defence Ministry said in comments carried by the Interfax news agency.
The helicopter was returning to the Khmeimim air base on Syria's north-western coast after delivering humanitarian aid to the city of Aleppo when it was shot down by fire from the ground, the ministry said.
Photos circulated by a pro-rebel news channel on the Telegram messaging app, popular in Syria, purported to show a Russian military man being dragged on the ground after the helicopter crash.
Last week, Russia announced that it was beginning a large-scale humanitarian operation in Syria's northern city of Aleppo.
Russia has been supporting its longtime ally, the Syrian government, with a military campaign since last year in an effort to restore some stability to the country.