A plunging meteor exploded with a blinding flash above central Russia on Friday, sowing panic as the hurtling space debris set off a shockwave that smashed windows and hurt almost 1, 000 people.
The extraordinary event brought morning traffic to a sudden halt in the Urals city of Chelyabinsk as shocked drivers stopped to watch the falling meteor partially burning up in the lower atmosphere and light up the sky.
The emergencies ministry said 474 people were wounded, 14 of them seriously, by the damage caused mainly to window pains by shockwave in Chelyabinsk and other towns in the Urals. Mobile communications were temporarily cut.
It was not clear if the meteor's entry into the atmosphere was linked to the asteroid 2012 DA 14 which is expected to pass about 17,200 miles (27,000 kilometres) above the Earth later Friday in an unusually close approach.
"At 0920 (0320 GMT) an object was observed above Chelyabinsk which flew by at great speed and left a trail behind. Within two minutes there were two bangs," regional emergencies official Yuri Burenko said in a statement.
"The shockwave broke glass in Chelyabinsk and a number of other towns in the region," he said.
The office of the local governor said in a statement that a meteorite had fallen into a lake outside the town of Chebakul in the Chelyabinsk region. This was not confirmed by federal officials, who insisted any fragments were yet to be found.
There were no reports that any locals had been hurt directly by a falling piece of meteorite. The defence ministry meanwhile said it had sent soldiers "to the sites of impact", without giving further details.
Schools were closed for the day and theatre shows cancelled across the region after the shock wave blew out windows amid temperatures as low as minus 18 degrees Celsius (zero degrees Fahrenheit).
The local postal service said several of its buildings had been damaged while the stadium of Chelyabinsk's Traktor ice hockey side was also hit, forcing the cancellation of a match.
State television showed a part of the roof and a wall also shorn off a brick zinc factory in the city of Chelyabinsk. Other images showed people with bloodied faces and at least one child's back covered with blood.
-- 'A large object weighing tonnes' --
The meteor "was quite a large object with a mass of several dozen tonnes," estimated Russian astronomer Sergei Smirnov of the Pulkovo observatory in an interview with the Rossia 24 channel.
NASA estimates that a smallish asteroid such as the 2012 DA 14 flies close to Earth every 40 years but only hits our planet once every 1,200 years.
But the Chelyabinsk meteor explosion appears to be one of the most stunning consmic events above Russia since the 1908 Tunguska Event when a massive blast most scientists blame on an asteroid or a comet impact ripped through Siberia.
With the event already becoming a leading trend on Twitter, locals posted amateur footage on YouTube showing men swearing in surprise and fright, and others grinding their cars to a halt.
"First I thought it was a plane falling, but there was no sound from the engine... after a moment a powerful explosion went off," said witness Denis Laskov.
"In a lot of the houses on our street the windows were blown out," he told state television.
Footage is viewable on: http://www.youtube.com/watch?feature=player_embedded&v=_nOaRpF0DJk.
The Chelyabinsk region is Russia's industrial heartland, filled with smoke-chugging factories and other huge facilities that include a nuclear power plant and the massive Mayak atomic waste storage and treatment centre.
A spokesman for Rosatom, the Russian nuclear energy state corporation, said that its operations remained unaffected.
"All Rosatom enterprises located in the Urals region -- including the Mayak complex -- are working as normal," an Rosatom spokesman told Interfax.
The emergencies ministry said radiation levels in the region also did not change and that 20,000 rescue workers had been dispatched to help the injured and locate those requiring help.