"Repair work is taking place at the substation, during which new equipment is being tested. A new transformer, not connected to the power grid, was being tested and a fire broke out. This will not affect the work of the substation itself," said Olga Kindyashova.

The alarm concerning a fire on the territory of the substation was raised at 5:20 p.m. Moscow time (13:20 GMT).

There are no reports of injuries.

Firefighters are at the scene. The fire has been classed as a level 'two', with the maximum being five.