Deadly rocket explosion causing 'Radiation Spike' kills five in Russia, several injured

At least five people including three nuclear agency staff were killed and four others injured after the explosion of a rocket engine during a naval test range in Northern Russia led to a rise in radiation levels earlier on Thursday, according to the Defence Ministry of the country. The mishap occurred at a military shooting range in Nyonoksa in the northwestern Arkhangelsk region, causing a fire.

The ministry said a total of six servicemen and civilian engineers were injured, and three of them later died of injuries. However, there was no release of radioactivity or any toxic substances, but the local administration in Severodvinsk about 30 kilometers (about 19 miles) east from Nyonoksa reported a brief increase in radiation levels, it added.

Nyonoksa hosts a navy facility that serves as a base for testing intercontinental ballistic missiles intended for nuclear submarines.

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The explosion followed a massive fire that erupted Monday at a military ammunition depot near Achinsk in eastern Siberia's Krasnoyarsk region. The blaze triggered powerful explosions that continued for about 16 hours, killing one person, injuring another 13 and forcing over 16,500 people to flee their homes.

Meanwhile, a senior US official belonging to the Donald Trump administration expressed deep skepticism over Moscow's explanation wih regard to the blast, adding that the it could have involved with a nuclear powered missile. "We continue to monitor the events in the Russian far north but Moscow’s assurances that ‘everything is normal’ ring hollow to us," the official told Reuters on condition of anonymity.

Jeffrey Lewis, director of the East Asia Non-Proliferation Program at the Middlebury Institute of International Studies, on the other hand, said deconstruction of a facility for test-launching the nuclear-powered missile at a site in Novaya Zemlya could be the reason behind the blast.

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Based on commercial satellite pictures and other data, Lewis and his team said the ship used during the test is not generally required for a conventional missile tests, but for recovering a nuclear propulsion unit from the sea floor.