An Antonov An-26 went missing near the Russian city of Khabarovsk during a routine check of airport communications equipment.

The aircraft belonged to a company called Letnye Proverki I Sistemy (Flight Inspections and Systems) and carried six people onboard. It has been performing a check of ground communications systems.

According to Russian state news agency TASS, the aircraft was performing a low-level flight 38 kilometers (24 miles) from Khabarovsk airport as it disappeared from radars at 18:45 local time (8:45 pm UTC). 

Helicopters and ground vehicles of rescue services have been dispatched on a search of a crash site. The local prosecutor’s office has initiated an investigation of the event.

According to TASS, investigators say that the aircraft most likely collided with a hill due to either a navigation error or bad weather and poor visibility.

The An-26 is a twin-engine turboprop cargo and utility aircraft built by Antonov between 1969 and 1986. 

According to the website of Letnye Proverki I Sistemy, the company owns one An-26 and one An-24. It performs in-flight checks of communication systems of Russian airports