A meteor streaked across the sky and exploded over Russia's Ural Mountains with the power of an atomic bomb, its sonic blasts shattering countless windows and injuring about 1,100 people.
Many of the injured were cut by flying glass as they flocked to windows, curious about what had produced such a blinding flash of light. The meteor - estimated to be about 10 tons - entered the Earth's atmosphere at a hypersonic speed of at least 54,000kph (33,000mph) and shattered into pieces about 30-50 kilometres (18-32 miles) above the ground, the Russian Academy of Sciences said in a statement.
Amateur video showed an object speeding across the sky just after sunrise, leaving a thick white contrail and an intense flash.
"There was panic. People had no idea what was happening," said Sergey Hametov, a resident of Chelyabinsk, a city of one million about 1,500 kilometres (930 miles) east of Moscow. "We saw a big burst of light, then went outside to see what it was and we heard a really loud, thundering sound," he said.
The meteor hit less than a day before asteroid 2012 DA14 is to make the closest recorded pass by the Earth for a rock of its size - about 28,000 kilometres (17,150 miles). But the European Space Agency said its experts had determined there was no connection - just cosmic coincidence.
The meteor released several kilotons of energy above the region, the Russian science academy said. According to NASA, it was about 15 metres (49 feet) wide before it hit the atmosphere, about one-third the size of the passing asteroid.
Some meteorite fragments fell in a reservoir outside the town of Chebarkul. The crash left an eight-metre (26-foot)-wide crater in the ice. The shock wave blew in an estimated 100,000 square metres (more than 1 million square feet) of glass, according to city officials, who said 3,000 buildings in the city were damaged. At one zinc factory, part of the roof collapsed.
The Interior Ministry said about 1,100 people sought medical care after the shock wave and 48 of them were admitted to hospital. Most of the injuries were caused by flying glass, officials said.
Meteors typically cause sizeable sonic booms when they enter the atmosphere because they are travelling so much faster than the speed of sound. Injuries on the scale reported, however, are extraordinarily rare.
Jim Green, NASA's director of planetary science, called the back-to-back celestial events an amazing display. "This is indeed very rare and it is historic," he said on NASA TV. "These fireballs happen about once a day or so, but we just don't see them because many of them fall over the ocean or in remote areas. "