WATCH: Meteorite Crashes Over Russia A flaming meteorite crashed to the earth on Friday, injuring hundreds and reportedly prompting fears of an alien invasion. In scenes reminiscent of a Hollywood blockbuster, a series of explosions rocked the skies above the Ural Mountains and sparked panic in the three major cities of Chelyabinsk, Yekaterinburg and Tyumen. PHOTOS: LIFE With the Astrochimps: Early Stars of the Space Race Witnesses described how buildings shook, glass shattered and cellphones and internet connections stopped working. Amateur footage was also posted of the object causing windows to break before crashing into a wall at a zinc factory. Around 500 people are believed to have suffered minor injuries, mainly due to broken glass, while initial radiation levels were normal. Testing will continue throughout the day, officials said. The Russian Academy of Sciences is of the opinion that the meteor that streaked into the skies over the Urals and caused shock waves weighed roughly 10 tons (11 tons avoirdupois). In a statement Friday, the academy said the meteor entered the Earth's atmosphere at a speed of at least 54,000 kph (33,000 mph) and shattered about 30-50 kilometers (18-32 miles) above ground. Russia Today published unconfirmed reports that the meteorite was blown to pieces by a missile salvo from an air defense unit at the Urzhumka settlement near Chelyabinsk while at an altitude of 20 km. The channel also said that some onlookers thought a UFO was responsible for the spectacle. Russia's Emergency Ministry reported that 20,000 rescue workers were operating in the area to help alleviate any impact from the incident, and three aircraft were surveying the area to prioritize efforts. "According to preliminary data, the flashes seen over the Urals were caused by [a] meteorite shower," the Emergency Ministry told Itar-Tass news agency. Chelyabinsk regional authority published a message on its website that urged residents to pick up their children from school and remain at home. MORE: An All-Wet Meteorite Arrives from Mars