One died and more than 6,000 people were evacuated in central Russia after a series of massive explosions at an arms depot sprayed shells across several kilometres, the emergency situations ministry said Wednesday.
The blasts began Tuesday night and continued sporadically on Wednesday evening after a stockpile of old munitions started detonating and sparked a blaze at the depot near the town of Chapayevsk in the Samara region about 1,000 kilometres (600 miles) southeast of Moscow.
The depot contained around 18 million shells, the regional Investigative Committee said.
Almost 6,500 residents were evacuated from the settlement of Nagorny around five kilometres from the depot after the force of the blast and the shrapnel smashed windows, the emergency ministry said.
One man, a gas company employee who was carrying out work at the depot, died in the blaze, the emergency situations ministry said.
"The circumstances of his death are unknown," ministry spokesman Oleg Voronov told Rossiya 24 television.
A total of 41 people needed medical treatment and 10 were hospitalised, the regional emergency situations ministry said.
The cause of the blasts was unclear as investigators said the explosions appeared to have started spontaneously and could have been sparked by a wildfire outside the depot.
Russian television showed huge columns of black smoke and bright orange flames rising from the depot when the blasts destroyed four buildings. The blaze was contained but continued on Wednesday evening.
Explosives experts made safe around 12,000 unexploded shells, many of which were scattered on a nearby highway, an emergency ministry official, Nikolai Vdovin, told Russian news agencies.
Television footage showed blown-out glass and window frames and unexploded shells lying in Nagorny and on the nearby highway.
Drivers whose cars were hit by shrapnel were those most seriously injured.
"We were driving along and then there was an explosion and the force of it blew out all the windows in the car," a bloodied casualty told Rossiya 24.
Regional investigators launched a criminal probe into a breach of safety regulations and President Vladimir Putin ordered payments of 10,000 rubles ($300) to each of those evacuated.
Such accidents occur frequently at Russian arms depots that store vast stockpiles of old munitions in primitive conditions with little regard to public safety, and often close to settlements.
In October 2012, a depot containing 4,000 tonnes of munitions exploded in the Urals region, causing thousands of people to be evacuated.
In May 2012, a similar incident claimed the lives of six soldiers in the Nizhny Novgorod region of central Russia.