A meteor that scientists estimate weighed nine tonnes streaked at supersonic speed over Russia's Ural Mountains on Friday, setting off blasts that injured some 500 people and frightened countless more.
The Russian Academy of Sciences said in a statement that the meteor over the Chelyabinsk region entered the Earth's atmosphere at a speed of at least 54,000 km/h and shattered about 30 to 50 kilometres above ground.
The fall caused explosions that broke glass over a wide area. The Emergency Ministry says more than 500 people sought treatment after the blasts and that 34 of them were hospitalized.
"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 1,500 kilometres 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, Alexander Yakovets, told CBC News he was woken in his eighth-floor apartment by a "really horrible sound" that he first thought might have been a terrorist attack or a military exercise.
He said he saw a very bright light and heard multiple explosions.
"For a couple of minutes, I thought [the building] was going to fall down," he said.
Resident Valya Kazakov said some elderly women in his neighbourhood started crying out that the world was ending.
Some fragments 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.
The agency also cited military spokesman Yarslavl Roshupkin as saying that a six-metre-wide crater was found in the same area which could be the result of fragments striking the ground.
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 Friday, however, are extraordinarily rare.
Interior Ministry spokesman Vadim Kolesnikov said that about 600 square metres 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 spokeswoman for the Emergency Ministry, Irina Rossius, told The Associated Press that 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.
'An exploding fireball event'Amateur video 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.
Donald Yeomans, manager of U.S. Near Earth Object Program 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 metres in extent before entering the atmosphere, fragmenting and exploding due to the unequal pressure on the leading side vs. the trailing side (it pancaked and exploded)," Yeoman said in an email to The Associated Press.
"It is far too early to provide estimates of the energy released or provide a reliable estimate of the original size," Yeomans added.
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 28,000 kilometres.
But the European Space Agency, in a post on its Twitter account, said its experts had determined there was no connection.
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 RIA Novosti news agency reported.
Deputy Prime Minister Dmitry Rogozin said the incident showed the need for leading world powers to develop a system to intercept objects falling from space.
"At the moment, neither we nor the Americans have such technologies" to shoot down meteors or asteroids, he said, according to the Interfax news agency.