Nyonoksa hosts a navy facility that serves as a base for testing intercontinental ballistic missiles (Picture: Google Earth).
Russia's top nuclear official is promising to succeed in developing new weapons, after an explosion during tests in the country last week.
Five scientists were reported killed in what the US believes was a failed test of a new missile system.
A spike in radiation levels nearby led to fears the failed test involved a nuclear-powered cruise missile.
Donald Trump said on Twitter the US had "similar, though more advanced, technology".
Thousands of people attended the burials of the Russian nuclear engineers who were killed.
They were laid to rest on Monday in the city of Sarov that hosts Russia's main nuclear weapons research centre.
Soon after Thursday's explosion, the Russian Defence Ministry said two people died and four were injured, including servicemen and civilian engineers.
It was not immediately clear if the five fatalities cited in a Saturday statement by Rosatom, Russia's nuclear agency, were in addition to the previously reported deaths.
Rosatom said the explosion occurred while the engineers were testing "a nuclear isotope power source" for a rocket.