Two people were killed and six were wounded when a rocket engine exploded Thursday during a test, Russia’s Defence Ministry says.

The ministry said the explosion occurred at a military shooting range in Nyonoksa in the northwestern Arkhangelsk region, causing a fire. 

Two soldiers were killed and six servicemen and civilian engineers were injured and hospitalized, the Russian News Agency TASS reports, citing the ministry.

The Defence Ministry said there was no release of radioactivity or any toxic substances, but the local administration in Severodvinsk about 30 kilometres east from Nyonoksa reported a brief increase in radiation levels.

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

Russia closed off an area of the White Sea to shipping for a month after the fatal explosion, the country’s Interfax news agency reports, citing a port official in the Dvina Bay area of the sea.

Thursday’s explosion followed a massive fire on Monday at a military ammunition depot near Achinsk in eastern Siberia’s Krasnoyarsk region.

That 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.