Russian federal prosecutors have identified the operator of the Antonov An-12 missing in the far east of the country as Avis-Amur, the aircraft having been on lease from its owner, Komsomolsk-on-Amur airframer KnAAPO.
Preliminary indications, said the Russian emergencies ministry, point to a fuel leak and fire in one of the starboard engines of the four-engined transport.
The aircraft had 11 on board, eight of them crew members, it added. It was operating a freight flight from Magadan to the regional airport of Keperveym, in the Chukotka district.
It was in the vicinity of Omsukchan, 310km from Magadan, when the An-12's captain opted to descend and return to Magadan. The incident occurred at about 14:45 local time.
"Communication with the aircraft was [then] lost," said the ministry. Mil Mi-8 and Antonov An-26 aircraft were enlisted to aid the search for the missing transport, but poor weather has hampered the effort. Rescuers are also planning to use a Beriev Be-200 in the search.
The prosecutor's office stated that there was 16t of food produce on board the freighter. Magadan airport's ground services had been alerted to the planned return, but the prosecutor said the aircraft lost radio communications shortly afterwards and "disappeared from the radar".
Khabarovsk-based Avis-Amur's operations will be checked, as routine, for compliance with safety regulations, the prosecutor added.