A meteor streaked across the sky and exploded over central Russia on Friday, raining fireballs over a wide area and causing a shock wave that smashed windows, damaged buildings and injured more than 1,000 people.
People heading to work in Chelyabinsk heard what sounded like an explosion, saw a bright light and then felt the shock wave, according to a Reuters correspondent in the industrial city 1,500 km (950 miles) east of Moscow.
The fireball, travelling at a speed of 30 km (19 miles) per second according to Russian space agency Roscosmos, had blazed across the horizon, leaving a long white trail that could be seen as far as 200 km (125 miles) away.
Car alarms went off, thousands of windows shattered and mobile phone networks were disrupted. The Interior Ministry said the meteor explosion, a very rare spectacle, also unleashed a sonic boom.
"I was driving to work, it was quite dark, but it suddenly became as bright as if it were day," said Viktor Prokofiev, 36, a resident of Yekaterinburg in the Urals Mountains.
"I felt like I was blinded by headlights."
The meteor, which weighed about 10 tons and may have been made of iron, entered Earth's atmosphere and broke apart 30-50 km (19-31 miles) above ground, according to Russia's Academy of Sciences.
No deaths were reported but the Emergencies Ministry said 20,000 rescue and clean-up workers were sent to the region after President Vladimir Putin told Emergencies Minister Vladimir Puchkov to ease the disruption and help the victims.
The Interior Ministry said about 1,200 people had been injured, at least 200 of them children, and most from shards of glass.
The region of Chelyabinsk has long been a hub for the Russian military and defense industry, and it is often the site where artillery shells are decommissioned.
A local Emergencies Ministry official said meteor storms were extremely rare and Friday's incident may have been connected with an asteroid the size of an Olympic swimming pool that was due to pass Earth.
But an astronomer at Russia's Academy of Sciences, Sergei Barabanov, poured doubt on that report. He said there was no evidence to support the theory that the meteor had travelled with the asteroid or had broken off from it.
The European Space Agency, on its Twitter microblog, also said its experts had confirmed there was no link.
The regional governor in Chelyabinsk said the meteorite shower had caused more than $30 million in damage, and the Emergencies Ministry said some 300 buildings had been affected.
One piece of meteorite broke through the ice of nearby Cherbakul Lake, leaving a hole several meters wide.
Despite warnings not to approach any unidentified objects, some enterprising locals were hoping to cash in.
"Selling meteorite that fell on Chelyabinsk!" one prospective seller, Vladimir, said on a popular Russian auction website. He attached a picture of a black piece of stone that on Friday afternoon was priced at 1,488 roubles ($49.46).
WINDOWS BREAK, FRAMES BUCKLE
The early morning blast and ensuing shock wave blew out windows on Chelyabinsk's central Lenin Street, buckled some shop fronts and rattled apartment buildings in the city center.
"I was standing at a bus stop, seeing off my girlfriend," said Andrei, a local resident who did not give his second name. "Then there was a flash and I saw a trail of smoke across the sky and felt a shock wave that smashed windows."
Chelyabinsk city authorities urged people to stay indoors unless they needed to pick up their children from schools and kindergartens.
A wall was badly damaged at the Chelyabinsk Zinc Plant but a spokeswoman said no environmental threat resulted.
In 1908, a meteorite is thought to have devastated an area of more than 2,000 sq km (1,250 miles) in Siberia, breaking windows as far as 200 km (125 miles) from the point of impact.
The Emergencies Ministry described Friday's events as a "meteor shower in the form of fireballs" and said background radiation levels were normal. It urged residents not to panic.
Simon Goodwin, an astrophysics expert from Britain's University of Sheffield, said that roughly 1,000 to 10,000 tons of material rained down from space towards the earth every day, but most burned up in the atmosphere.
"While events this big are rare, an impact that could cause damage and death could happen every century or so. Unfortunately there is absolutely nothing we can do to stop impacts."
The meteor struck just as an asteroid known as 2012 DA14, about 46 meters (yards) in diameter, was due to pass closer to Earth - at a distance of 27,520 km (17,100 miles) - than any other known object of its size since scientists began routinely monitoring asteroids about 15 years ago.