MOSCOW, August 11. /TASS/. The fire outbreak and subsequent explosion near the city of Severodvinsk occurred when testing a missile on a sea-based platform, Communications Department of the Russian state corporation Rosatom told TASS.

"Missile tests were held on the sea-based platform. Missile fuel inflammation with further detonation occurred after completion of tests. Several staff members were thrown away to the sea and there was a hope to find them alive. The search continued until the hope to find survivors was present. The death of five Rosatom employees dealing with work related to a radio isotope power source being part of the missile was announced only after that," the department said.

"The concourse of factors was present, which often takes place when testing new technologies," a spokesman of Rosatom said.

The accident occurred at a military testing range near Severodvinsk in the Arkhangelsk region on August 8. The Russian Defense Ministry initially said that two people died in the accident involving a liquid-fuel jet engine. Later regional authorities said that six more people have been hospitalized after the accident. On August 10, Rosatom said that five employees were killed in the accident and three more were hospitalized.