At least 12 people have died in the Russian city of Kopaysk, about 1,600 kilometers from the Ukrainian border, after an explosion at an ammunition factory.

The powerful explosion occurred on Wednesday night with Russian authorities yet to officially announce the cause of the incident.

The plant, according to Russian media, is one of the main ammunition production facilities in the Chelyabinsk region. Search and rescue operations are ongoing, while authorities have blocked access to the area.

The police are continuing their operations and the police have been unable to reach the area.