The incident happened last month at a dump for nuclear waste in the north western Murmansk region, Nikolai Chingarev, spokesman for the Nuclear Energy Ministry, said.

"However, there is no risk to their health," he told AFP, adding an internal inquiry was underway.

A Norwegian-based international ecologist organisation, Bellona, first reported the August 20 incident.

Dismantled parts of former nuclear submarines are stored at the site at a garrison of Russia's Northern Fleet in the village of Gremikha, Sergey Javoronkine, Bellona's regional official, told AFP.

He blamed "crude violations of safety rules" for the incident.

TERRA.WIRE