At least five people were killed and three injured after a rocket exploded during tests at a military site in northern Russia, the state nuclear energy company Rosatom said on Saturday.
Rosatom said the accident occurred during tests on a liquid propellant rocket engine on Thursday, RIA reported. Officials said the three injured staff members suffered serious burns in the accident. and were receiving the necessary medical treatment.
It was previously reported that two people were killed in the accident and a nearby city reported a rise in radiation levels when the incident took place at the testing site in Nyonoksa.
Rosatom's engineering and technical division had been working on "isotope power source" for a propulsion system, the company told Russian media.
The Russian Defence authorities had initially said that no harmful chemicals were released into the atmosphere and that radiation levels were unchanged.
However, the radiation levels rose 20 times higher than normal, 2 microsieverts per hour, for about 40 minutes before returning to normal 0.11 microsieverts, Severodvinsk administration said. Both levels are too small to cause radiation poisoning. The city is located 47 km away from the explosion site in Nyonoksa.
The Reuters reported that the statement by Severodvinsk administration was taken down from the Internet on Friday without explanation. Officials responded to media inquiries on the statement said that it was taken down "because this incident comes under the authority of the defence ministry," reported the BBC.
The incident resulted in high demand for iodine in pharmacies which was reported to be running out in the nearby Arkhangelsk and Severodvinsk cities.
"Yesterday it was all sold out," said a pharmacist in Arkhangelsk told Russia's Interfax news agency on Friday.
"The excitement started at about five o'clock, and they bought all of it before we closed. At the checkout, people were discussing the news about radiation in Severodvinsk, the explosion at the military site."
Iodine is said to block the thyroid's glands from absorbing radioactive iodine and help protect the gland from radiation injury. The pills can also cause adverse medical issues.
While the details of the weapons system remained uncertain, media reported that the Nyonoksa naval site is known to carry out tests for its missile systems including intercontinental ballistic missiles, cruise missiles and anti-aircraft missiles. The site also includes nuclear-powered submarines.