"I can assure you that, naturally, all relevant government agencies are doing everything possible to guarantee the complete safety of Russian citizens; there should be no doubts about this", Peskov said.
The Russian Defence Ministry said that there had been no emissions of harmful substances into the atmosphere following the explosion, adding that the radiation background was normal.
On 10 August, Rosatom said that five of its employees had died in an explosion that happened on 8 August during tests of a liquid-propellant rocket engine at a military site in the Arkhangelsk Region.
It added that the accident took place during engineering and technical works on isotope sources of the engine.
All those wounded had been hospitalised, Rosatom pointed out, expressing condolences to the families of the accident victims.