MOSCOW -- Debris from a meteor streaked through the sky with a blinding flash in western Siberia early Friday, creating a thunderous shock wave that damaged buildings across a vast territory. Russia's Interior Ministry said about 1,200 people were injured, 200 of them children, mostly from shards of shattered glass.
Many of the injuries were reported in the city of Chelyabinsk, about 950 miles east of Moscow, in a region where there are many factories for defense, including nuclear weapons production. But there was no indication of damage that resulted in any radiation leaks, officials said.
The blast was caused by a 10-ton meteor, of a type known as a bolide, which created a powerful shock wave when it hit the Earth's atmosphere, the Russian Academy of Sciences said in a statement. Scientists believe the bolide exploded and evaporated at a height of about 20 to 30 miles above the Earth's surface, but that small fragments -- meteorites -- may have reached the ground, the statement said.
The governor of the Chelyabinsk district reported that material from the sky had fallen into a lake on the outskirts of a city about 50 miles west of Chelyabinsk. Officials told Russian news agencies that they had sent police officers there.
The meteor event came hours before a small asteroid, known as 2012 DA14, passed close to Earth on Friday, which NASA was tracking on its Web site. Aleksandr Y. Dudorov, a physicist at Chelyabinsk State University, said it was possible that the meteorite may have been flying alongside the asteroid.
"What we witnessed today may have been the precursor of that asteroid," said Mr. Dudorov in a telephone interview.
Others, however, disputed that view, saying there was almost certainly no connection. The Jet Propulsion Laboratory, part of NASA, said in a statement posted earlier on its Web site that "preliminary information indicates that the fireball in Chelyabinsk, Russia, is not related to asteroid 2012 DA14, which is flying by Earth today."
Prof. Alan Fitzsimmons, an astronomer at the Astrophysics Research Centre at Queen's University Belfast, told the BBC that 2012 Da14 approached Earth from the south, while the meteor struck the Earth's atmosphere in the northern hemisphere, indicating that the objects were traveling in different directions. "This is literally a cosmic coincidence, although a spectacular one," he said.
Fiery meteors are not unusual, but they typically evaporate far above the Earth's surface, the Russian Academy of Sciences said in its statement. This meteor was unusual because it was so hard, and may have been made of iron, the statement said. Nothing similar has been recorded on Russian territory since 2002.
Video clips from Chelyabinsk showed an early morning sky illuminated by a brilliant flash, followed by the sound of breaking glass and multiple car alarms. Meteors typically cause sonic booms as they enter the Earth's atmosphere. On Friday, the force was powerful enough to shatter dishes and televisions in people's homes.
"I saw a flash in the window, turned toward it and saw a burning cloud, which was surrounded by smoke and was going downward -- it reminded me of what you see after an explosion," said Maria Polyakova, 25, head of reception at the Park-City Hotel in Chelyabinsk. A video made outside a building in Chelyabinsk captured the astonished voices of people who were uncertain what it was they had just seen.
"Maybe it was a rocket," said one man, who rushed outside onto the street with his co-workers after hearing the blast far out of sight. A man named Artyom, who spoke to the Moscow FM radio station, said the explosion was enormous.
"I was sitting at work and the windows lit up and it was as if the whole city was illuminated, and I looked out and saw a huge streak in the sky and it was like that for two or three minutes and then I heard these noises, like claps," he said. "And then all the dogs started barking."
He said the blast caused balconies to shake and windows to shatter. He said he did not believe it was a meteor. "We are waiting for a second piece, that is what people are talking about now," the man said.
The object was visible from the city of Nizhniy Tagil, around 220 miles north of Chelyabinsk, where so many people called an emergency assistance number that it stopped working, the Novy Region news service reported.
The government response on Friday was huge. Seven airplanes were deployed to search for places where meteorites might have fallen and more than 20,000 people dispatched to comb the area on foot, according to the Ministry of Emergency Situations. There were also 28 sites designated to monitor radiation. No unusual readings had been detected, the ministry reported.
The area around Chelyabinsk, just east of the Ural Mountains at the western edge of Siberia, is home to "dozens of defense factories, including nuclear factories and those involved in production of thermonuclear weapons," said Vladimir Lipunov, an astrophysicist at the Shternberg State Astronomy Institute.
"No one needs to be told what the Urals is," Mr. Lipunov told the NTV television station. "A second hit in the same area is unlikely and everything could have been much, much worse."
Siberia stretches the length of Asia, and there is a history of meteor and asteroid showers there. In 1908 a powerful explosion was reported near the Tunguska River in central Siberia, its impact so great that an estimated 80 million trees were flattened over hundreds of square miles. Generations of scientists have studied that event, analyzing particles that were driven into the Earth's surface as far away as the South Pole. An article published on the NASA Web site on June 30, 2008, the centennial of the Tunguska impact, said the object, weighing about 220 million pounds during its plunge, heated the surrounding air to 44,500 degrees Fahrenheit and exploded in a fireball that released the energy equivalent of 185 Hiroshima atomic bombs.
In the United States, NASA alluded to the Tunguska incident when it said that it was watching closely as the asteroid 2012 DA14, 150 feet in diameter, is expected to whiz past Earth on Friday at a distance of around 17,200 miles, the closest for many decades.
In a statement on its Web site, NASA said Friday that there was no risk that 2012 DA14 would collide with Earth. But it would pass within "the belt of satellites in geostationary orbit, which is 22,200 miles above Earth's surface."
The asteroid passed Earth at 2:24 p.m. Eastern time, at an altitude of about 17,200 miles.
Although the asteroid passed Earth safely, NASA said, "if another asteroid of a size similar to that of 2012 DA14 were to impact Earth, it would release approximately 2.5 megatons of energy in the atmosphere and would be expected to cause regional devastation."
Viktor Klimenko contributed reporting from Moscow, Alan Cowell from London and Rick Gladstone from New York.
This article originally appeared in The New York Times.