Many of the injured on Friday were hurt by broken glass.
"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 1500km 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.
Another Chelyabinsk resident, Valya Kazakov, said some elderly women in his neighbourhood started crying out that the world was ending.
Some meteorites – fragments of the meteor – fell in a reservoir outside the town of Cherbakul, the regional governor's office said, according to the Itar-Tass news agency. It was not immediately clear if any people were struck by fragments.
Meteors typically cause sizeable sonic booms when they enter the atmosphere because they are travelling much faster than the speed of sound. Injuries on the scale reported on Friday, however, are extraordinarily rare.
Injuries and damage
Interior Ministry spokesperson Vadim Kolesnikov said more than 400 people had sought medical treatment after the blasts, and at least three had been hospitalised in serious condition. Many of the injuries were from glass broken by the explosions.
Kolesnikov also said about 600 square meters of a roof at a zinc factory had collapsed. There was no immediate clarification of whether the collapse was caused by meteorites or by a shock wave from one of the explosions.
Reports conflicted on what exactly happened in the clear skies. A spokesperson for the emergency ministry, Irina Rossius, said that there was a meteor shower, but another ministry spokesperson, Elena Smirnikh, was quoted by the Interfax news agency as saying it was a single meteor.
Amateur video broadcast on Russian television showed an object speeding across the sky about 5.20am local time, leaving a thick white contrail and an intense flash.
Donald Yeomans, manager of US Near Earth Object Programme in California, said he thought the event was probably "an exploding fireball event".
"If the reports of ground damage can be verified, it might suggest an object whose original size was several meters in extent before entering the atmosphere, fragmenting and exploding due to the unequal pressure on the leading side versus the trailing side [it pancaked and exploded]," Yeoman said.
"It is far too early to provide estimates of the energy released or provide a reliable estimate of the original size," Yeomans added.
'Weapon by the Americans'
Russian news reports noted that the meteor hit less than a day before the asteroid 2012 DA14 is to make the closest recorded pass of an asteroid – about 28 000km.
But the European Space Agency, in a post on its Twitter account, said its experts had determined there was no connection.
Small pieces of space debris – usually parts of comets or asteroids – that are on a collision course with the Earth are called meteoroids. When meteoroids enter the Earth's atmosphere they are called meteors. Most meteors burn up in the atmosphere, but if they survive the frictional heating and strike the surface of the Earth they are called meteorites.
The dramatic events prompted an array of reactions from prominent Russian political figures. Prime Minister Dmitry Medvedev, speaking at an economic forum in the Siberian city of Krasnoyarsk, said the meteor could be a symbol for the forum, showing that "not only the economy is vulnerable, but the whole planet".
Vladimir Zhirinovsky, the nationalist leader noted for vehement statements, said: "It's not meteors falling, it's the test of a new weapon by the Americans," the Russian International News Novosti agency reported. – AP