MOSCOW (CBS/AP) -- A meteor streaked across the sky above Russia's Ural Mountains on Friday morning, causing sharp explosions and injuring more than 400 people, many of them hurt by broken glass.
Fragments of the meteor fell in a thinly populated area of the Chelyabinsk region, the Emergency Ministry said in a statement. About 6,000 square feet of a roof at a zinc factory collapsed, but it was unclear whether that was caused by meteor fragments impacting the building, or by a shock wave from a nearby impact.
"There was panic. People had no idea what was happening. Everyone was going around to people's houses to check if they were OK," said Sergey Hametov, a resident of Chelyabinsk, about 930 miles east of Moscow, the biggest city in the affected region.
"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.
Amateur videos posted to Youtube showed a bright streaks of light crossing the morning sky. In some videos, a large boom was heard -- possibly an impact or possibly a sonic boom of the meteor sailing through the Earth's atmosphere at more than the speed of sound.
Reports conflicted on what exactly happened in the clear skies. A spokeswoman for the Emergency Ministry, Irina Rossius, told The Associated Press there was a meteor shower, but another ministry spokeswoman, Elena Smirnikh, was quoted by the Interfax news agency as saying it was a single meteor.
At least part of the event was captured on amateur video. Some broadcast on Russian television showed an object speeding across the sky about 9:20 a.m. local time, leaving a thick white contrail and an intense flash.
Interior Ministry spokesman Vadim Kolesnikov said more than 400 people had sought medical treatment after the blasts, and at least three had been hospitalized in serious condition. Many of the injuries were from glass broken by the explosions.
The meteor hit less than a day before the asteroid 2012 DA14 is to make the closest recorded pass of an asteroid -- about 17,150 miles. European Space Agency spokesman Bernhard Von Weyhein said, however, that there was no connection with the meteor over Russia, it was just a cosmic coincidence.
Meteors are pieces of space rock, usually from larger comets or asteroids, which enter the Earth's atmosphere. Many are burned up by the heat of the atmosphere, but those that survive and strike the Earth are called meteorites. They often hit the ground at tremendous speed -- up to about 19,000 miles an hour, according to the European Space Agency. That releases a huge amount of force.
Experts say smaller strikes happen five to 10 times a year. Large impacts such as the one Friday in Russia are rarer but still occur about every five years, according to Addi Bischoff, a mineralogist at the University of Muenster in Germany. Most of these strikes happen in uninhabited areas where they don't cause injuries to humans.