Rosneft has stopped production at its east Siberian 140,000 bpd Achinsk refinery after a fire killed at least seven people, sources said on Monday.
Repairs to the facility could take up to six months, according to a source.
Rosneft said a fire broke out on Sunday evening at a fractionation unit of the refinery.
On Tuesday an Emergencies Ministry official said seven people had died, seven were injured, and two were missing.
A Rosneft spokesman declined to comment on the number of casualties or the effect on production.
