| Last updated
Russia's top nuclear agency has admitted its role in the explosion that killed five scientists last week.
In a statement released by Rosatom, the agency claimed the accident occurred during tests of 'isotopic power sources in a liquid propulsion system' last Thursday (8 August).
However, experts have since said they believe the tragic incident happened during tests of a new nuclear weapon, Burevestnik.
According to reports, rocket fuel caught fire during the test close to the port city of Severodvinsk, causing an explosion.
Though it was initially claimed that there was no rise in the level of radiation, following the blast, local officials stated there was a 40-minute spike, reaching two microsieverts per hour before falling back to the normal level of 0.11 microsieverts.
Neither, it is said, is enough to cause radiation sickness.
Residents of the village closest to the site will be evacuated Wednesday morning for two hours.
According to local reports, a train will be sent to take 450 locals from the village while work is carried out in the area.
Regional governor, Igor Orlov, said that the move is a 'routine measure' rather than an official evacuation, according to Interfax news agency.
A statement from Rosatom read: "Five Rosatom staff members died and a further three people were injured in a tragic accident that took place during tests on a liquid propulsion system involving isotopes at a military facility in Arkhangelsk region.
"We offer our deepest condolences, and all possible support, to the families and friends of those who died.
"Those injured have been admitted to hospital and are receiving treatment. Our thoughts are with the loved ones of all those affected."
The five engineers who were killed during the incident have been named as Alexey Vyushin, Yevgeny Koratayev, Vyacheslav Lipshev, Sergey Pichugin and Vladislav Yanovsky.
In another statement, Valentin Kostyukov, head of the nuclear centre, part of Russia's state nuclear agency Rosatom, praised the group for its bravery.
It read: "The testers are national heroes. These people were the elite of the Russian federal nuclear centre and have tested under some of the most incredibly difficult conditions."
US-based experts have since cast doubt on Russia's official explanation of the explosion, as they claim a a liquid rocket propellant would not release radiation.
Jeffrey Lewis, an arms-control expert at the Middlebury Institute of International Studies at Monterey, is one of those. He believes the Russians were testing a new nuclear weapon known by NATO as 'Skyfall', and dubbed 'Burevestnik' in Russia.
Speaking to CNN, he said: "We are skeptical of the claim that what was being tested was a liquid propellant jet engine. We think it was a nuclear-powered cruise missile that they call Burevestnik."
A senior official in the Trump administration also claimed the government was unsure about Russia's claims.
Speaking to Reuters, they said: "We continue to monitor the events in the Russian far north but Moscow's assurances that 'everything is normal' ring hollow to us."
Chosen for YouChosen for You
Most Read StoriesMost Read