Russian President Vladimir Putin has handed state awards to the widows of nuclear engineers who died when a new weapon exploded at the navy’s testing range.

Speaking in remarks televised Friday, Putin hailed the five men who died in the Aug. 8 incident in Nyonoksa on the White Sea and received posthumous awards. He said Russia will continue to develop the weapon involved in the incident, saying it will “ensure sovereignty and security for Russia and peace for our children.”

Putin didn’t name the weapon and Russian officials have offered scarce and contradictory information about the incident that led to a brief spike in radioactivity.

Rosatom nuclear state corporation said the explosion occurred on an offshore platform during tests of a "nuclear isotope power source" of a rocket engine.