MOSCOW (AP) -- With a blinding flash and a booming shock wave, a meteor blazed across the western Siberian sky Friday and exploded with the force of 20 atomic bombs, injuring more than 1,000 people as it blasted out windows and spread panic in a city of 1 million.
While NASA estimated the meteor was only about the size of a bus and weighed an estimated 7,000 tons, the fireball it produced was dramatic. Video shot by startled residents of the city of Chelyabinsk showed its streaming contrails as it arced toward the horizon just after sunrise, looking like something from a world-ending science-fiction movie.
The largest recorded meteor strike in more than a century occurred hours before a 150-foot asteroid passed within about 17,000 miles (28,000 kilometers) of Earth. The European Space Agency said its experts had determined there was no connection between the asteroid and the Russian meteor -- just cosmic coincidence.
The meteor above western Siberia entered the Earth's atmosphere about 9:20 a.m. local time (10:20 p.m. EST Thursday) at a hypersonic speed of at least 33,000 mph (54,000 kph) and shattered into pieces about 30-50 kilometers (18 to 32 miles) high, the Russian Academy of Sciences said. NASA estimated its speed at about 40,000 mph, said it exploded about 12 to 15 miles high, released 300 to 500 kilotons of energy and left a trail 300 miles long.
"There was panic. People had no idea what was happening," said Sergey Hametov of Chelyabinsk, about 1,500 kilometers (930 miles) east of Moscow in the Ural Mountains.
"We saw a big burst of light, then went outside to see what it was and we heard a really loud, thundering sound," he told The Associated Press by telephone.
The shock wave blew in an estimated 100,000 square meters (more than 1 million square feet) of glass, according to city officials, who said 3,000 buildings in Chelyabinsk were damaged. At a zinc factory, part of the roof collapsed.
The Interior Ministry said about 1,100 people sought medical care after the shock wave and 48 were hospitalized. Most of the injuries were caused by flying glass, officials said.
Scientists estimated the meteor unleashed a force 20 times more powerful than the Hiroshima bomb, although the space rock exploded at a much higher altitude. Amy Mainzer, a scientist at NASA's Jet Propulsion Laboratory, said the atmosphere acted as a shield.
The shock wave may have shattered windows, but "the atmosphere absorbed the vast majority of that energy," she said.
Emergency Situations Ministry spokesman Vladimir Purgin said many of the injured were cut as they flocked to windows to see what caused the intense flash of light, which momentarily was brighter than the sun.
There was no immediate word on any deaths or anyone struck by space fragments.
President Vladimir Putin summoned the nation's emergencies minister and ordered immediate repairs. "We need to think how to help the people and do it immediately," he said.
Some meteorite fragments fell in a reservoir outside the town of Chebarkul, the regional Interior Ministry office said. The crash left an eight-meter (26-foot) crater in the ice.
Lessons had just started at Chelyabinsk schools when the meteor exploded, and officials said 258 children were among those injured. Amateur video showed a teacher speaking to her class as a powerful shock wave hit the room.
Yekaterina Melikhova, a high school student whose nose was bloody and whose upper lip was covered with a bandage, said she was in her geography class when a bright light flashed outside.
"After the flash, nothing happened for about three minutes. Then we rushed outdoors. ... The door was made of glass, a shock wave made it hit us," she said.
Russian television ran video of athletes at a city sports arena who were showered by shards of glass from huge windows. Some of them were still bleeding.
Other videos showed a long shard of glass slamming into the floor close to a factory worker and massive doors blown away by the shock wave.
Meteors typically cause sizeable sonic booms when they enter the atmosphere because they are traveling so much faster than the speed of sound. Injuries on the scale reported Friday, however, are extraordinarily rare.
"I went to see what that flash in the sky was about," recalled resident Marat Lobkovsky. "And then the window glass shattered, bouncing back on me. My beard was cut open, but not deep. They patched me up. It's OK now."
Another resident, Valya Kazakov, said some elderly women in his neighborhood started crying out that the world was ending.