Two Russian military pilots were killed when their helicopter crashed near the central Syrian city of Homs, the defense ministry said on Tuesday, adding that the aircraft had not been under fire.

Two Russian military pilots were killed when their helicopter crashed near the central Syrian city of Homs, the defense ministry said on Tuesday, adding that the aircraft had not been under fire.

"Two crew members died," the defense ministry said in a statement.

The crash of the Mi-28 attack helicopter happened in the early hours of Tuesday, the ministry said, adding the bodies had been recovered and brought to Russia's Hmeimim air base.

"According to a report from the crash site, the helicopter was not fired at," the defense ministry added, saying experts were looking into the reasons of the accident.

The crash takes Russia's official combat death toll in Syria to seven.

Moscow says that five Russian servicemen perished while on combat duty in Syria, including the pilot of a warplane shot down by Turkey and a special operations officer who called an air strike on himself after being surrounded by terrorists of the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group near Palmyra.