An official mouthpiece for separatists in east Ukraine is citing a rebel official as saying an explosion at a coal mine has killed at least one person and trapped more than 70 workers underground.

Donetsk News Agency cited rescue services official Yuliana Bedilo as saying the explosion was caused by a mixture of gas and air — a common cause of industrial mining accidents.

The east of Ukraine has been wracked by fighting between government forces and Russian-backed rebels for almost a year, during which more than 6,000 people have been killed.

Bedilo was quoted as saying the incident at the Zasyadko mine in the rebel-controlled city of Donetsk was not caused by shelling. Rescue operations are said to be underway.