A Russian transport plane crashed on landing at Russia's Hmeimim airbase in Syria, killing all 32 on board, the defence ministry said in a statement carried by RIA Novosti.

The Defense Ministry says the An-26, with 26 passengers and six crew members onboard, crashed Tuesday 1,600 feet from the runway.

"The reason for the crash according to preliminary information could have been a technical fault," the ministry added, saying the plane had not come under fire.

Russia, a key ally of Syrian President Bashar Assad, leases a military base in Syria near the Mediterranean coast.

Moscow began conducting air strikes in Syria in September 2015, and its intervention has swung the nearly seven-year conflict firmly in favour of Assad.

The latest accident comes after a Sukhoi military jet crashed while trying to take off from Hmeimim in October last year, killing two crew.

Russia's most recent officially acknowledged military loss in battle in Syria was last month when a pilot was killed after his plane was downed over Idlib province.

Russia's official military losses in the war before the crash were 45.

Moscow last month also said that five citizens, not officially affiliated with the Russian military, were likely killed in the strikes in eastern Syria - the first admission of non-military combat casualties.