Russian news reports say a passenger airliner has crashed while landing in the city of Kazan and all 44 people aboard are believed to have been killed.

The reports said the Boeing 737 belonging to Tatarstan Airlines crashed about 7:20pm local time today.

There were no immediate indications of what may have caused the crash. Kazan is about 450 miles east of Moscow.

The ITAR-Tass news agency quoted a local representative of the Emergencies Ministry, Irina Rossius, as saying preliminary information indicated 44 people were aboard and all had died. The flight originated in Moscow.