The Russian Defense Ministry said that the military transport plane that crashed in Syria on Tuesday was carrying 39 people, instead of a previous report of 32, when the accident happened.

A total of 33 passengers and six crew members aboard the An-26 plane were killed after the aircraft hit the ground while landing in the Hmeymim airbase in Syria, according to the ministry.

The families of the deceased, all of whom were Russian servicemen, will be provided with necessary assistance and support.

Russian President Vladimir Putin extended condolences to the families and friends of those killed in the crash, according to the Kremlin.

The plane was not attacked and technical malfunction may have caused the crash, the Russian Defense Ministry said earlier in the day.

The Defense Ministry has set up a commission to investigate the crash.

Russia now uses the Hmeymim airbase to support Syrian government troops in the fight against terrorist groups in the country.

Tuesday's tragedy has been the deadliest air accident in Russia since a Tu-154 aircraft crashed in the Black Sea en route to the Hmeymim airbase in December 2016, killing all 92 people on board.