Reports from the Russian region of the Ural Mountains suggest that a meteor may have exploded 10,000 meters above the ground this morning. YouTube videos show loud blasts and bright objects falling from the sky, and an emergency official told Reuters that "It was definitely not a plane. We are gathering the bits of information and have no data on the casualties so far." The incident occurred in Chelyabinsk, about 1,500 kilometers (930 miles) east of Moscow.

"Preliminary indications are that it was a meteorite rain," said an emergency official speaking to RIA-Novosti. "We have information about a blast at 10,000-meter (32,800-foot) altitude. It is being verified." There are conflicting reports on what happened: an emergency ministry spokeswoman told the Associated Press that there was a meteor shower, but another account given to Interfax reported a single meteorite. Citing a Russian Interior Ministry spokesperson, the AP said that over 500 people have been injured, many by broken glass, but that number has since risen to around 950.

Local accounts provided to Reuters tell of burning objects in the sky followed by huge blasts that shattered windows and set off car alarms. The video above shows a bright white streak recorded from a dash-mounted camera, and below we see and hear closer evidence of the blast, with the white streak in the sky leading to a massive explosion — be warned, the video is loud. Many Russian drivers keep cameras on their dashboard in order to ensure evidence in the event of a traffic incident.

It's unclear what could have caused the explosions. Unconfirmed reports from Russia Today, a less than reliable source at the best of times, suggest that a meteor was blown away by a surface-to-air missile salvo, but there's little evidence of that from the videos we're seeing. A writer at ScienceBlogs, attempting to explain the notorious Tunguska incident that occurred in Russia over a century ago, provided an account of how meteors could explode in the atmosphere, but it's little more than speculation in this case.

Astronomer Phil Plait weighed in with his thoughts:

Plait has followed up with a blog post on Slate in which he reiterates his belief that the incident has no connection to 2012 DA14, the asteroid set to make a 17,200-mile "near miss" with the Earth later today.

This security camera footage shows the blinding effect on the ground below.

The Russian Academy of Science estimates that the meteor weighed 10 tons — about the same as eight cars — before it entered the Earth's atmosphere and began to break up.

Update: New reports indicate the meteor was in fact much larger — in the neighborhood of 10,000 tons.