One worker was killed and another seriously injured in an explosion yesterday on a decommissioned Russian nuclear submarine docked in the northern shipyard of Severodvinsk for dismantling.

There was no threat from radiation, Oleg Frolov, chief engineer of the Zvyozdochka shipyard, said on television. He said some diesel caught fire as workers dismantled an internal section of the submarine.

"There is no danger of any radioactive contamination of the surrounding territory as the reactor and nuclear fuel had already been removed for decommissioning," Mr Frolov said.

The Victor-III class nuclear submarine was built at the end of the 1970s and taken out of service last year for decommissioning.

A spokesman for the Defence Ministry said the fire had been put out and that a probe was underway into the incident.