The number of injured continues to rise as new reports come in from across a wide area.
Deputy Health Minister Igor Kagramanyan said 571 people had sought medical help, with 34 of them hospitalized, according to state-news agency Itar-Tass.
Vladimir Stepanov, of the National Center for Emergency Situations at the Russian Interior Ministry, earlier told state broadcaster Russia 24 that more than 500 had been injured and 22 hospitalized.
The vast majority of injuries are not thought to be serious.
About 270 buildings have sustained damage -- mostly broken glass -- as a result of the shock waves caused by the blast, Stepanov said, with hospitals, kindergartens and schools among those affected.
About 20,000 emergency response workers have been mobilized, state-run RIA Novosti news agency reported.
Amateur video footage showed a bright white streak moving rapidly across the sky, before exploding with an even brighter flash and a deafening bang.
The national space agency, Roscosmos, said scientists believed one meteoroid had entered the atmosphere, where it burned and disintegrated into fragments, according to RIA Novosti.
The resulting meteorites are believed to be scattered across three regions of Russia, one of them Chelyabinsk, as well as neighboring Kazakhstan, the news agency said.