Investigators are probing a hard landing involving a Boeing 767-300ER at Barnaul airport which resulted in a landing-gear fire and injuries to passengers as they evacuated the twinjet.

The aircraft had been operating flight ZF2244 on 25 September, from the Vietnamese city of Nha Trang.

Azur Air says the aircraft’s right-hand main landing-gear caught fire as it travelled along runway 24.

Russia’s emergency situation ministry for the Altai region states that the jet suffered a “hard landing” at around 21:21, before the fire broke out.

The aircraft appears to have carried out a missed approach prior to the touchdown.

After the landing the 767 stopped at the end of the runway and was evacuated. The fire was extinguished some 20min after the flight arrived.

There are contradictory figures about the level of injuries. The ministry says 334 passengers and 10 crew emerged from the aircraft, with no serious injuries, although 49 occupants sought medical assistance.

Azur Air indicates that at least three were transported to medical facilities with suspected fractures.

The federal Investigative Committee’s west Siberian transport division says it has opened a routine criminal probe into the event.

It says 56 passengers sustained injuries “of varying severity”.

Coincidentally the airport’s emergency services had carried out a simulated accident exercise the same day, to practice dealing with a fire on an aircraft.

This exercise involved an aircraft which had been hit by lightning, resulting in navigation system failure, and which suffered wing damage and fuel ignition on landing. It was performed using a Tupolev Tu-154 with the scenario featuring 56 passengers and six crew members.