Meteor: Rescue Teams Rally To Recovery Effort

A major recovery effort is under way to replace thousands of windows shattered by the shockwave from a meteor that exploded over Russia, as some 24,000 workers began arriving in the Chelyabinsk region to help relief efforts.

The shockwave blew out glass in more than 4,000 buildings in the region and injured about 1,200 people, largely with cuts from the flying debris.

Forty of those injured remained in hospital on Saturday, two of them in a serious condition, the state news agency RIA Novosti reported.

Regional governor Mikhail Yurevich said the damage from the high-altitude explosion - which was estimated to have been as powerful as 20 Hiroshima bombs - is estimated at 1bn rubles (£21m).

He promised to have the 200,000 square metres of broken windows replaced within a week.

Rescuers are also scouring the bottom of a lake for the remains of the meteor, which plunged to Earth in a fireball on Friday.

Part of the space rock, which was the size of a bus and blazed across western Siberia, is believed to have landed in the frozen Lake Chebarkul.

Curious onlookers gathered nearby were prevented from venturing out on to the lake by police as the search continued.

More than 24,000 rescuers and recovery workers have already been dispatched to the region around Chelyabinsk to help residents.

The workers will gather warm clothes and food, cover windows, and make other relief efforts. Crews from glass companies in adjacent regions have also begun to arrive.

Experts are also examining major buildings in case they have been structurally damaged by the blast.

Residents who had poured into the streets to watch the light show after spotting the initial flash were wounded by glass shattered by the subsequent sonic boom.

Experts said the meteor strike was the largest recorded in more than a century.

As the recovery mission begins in earnest, the emergencies ministry said six divers would be inspecting the lake for any pieces of meteorite.

Emergencies Minister Vladimir Puchkov added: "We have a special team working ... that is now assessing the seismic stability of buildings. We will be especially careful about switching the gas back on."

Scientists will be desperate to examine the rock for any clues about the cosmos but Mr Puchkov said no fragments had yet been discovered.

The explosion appears to have been one of the most stunning cosmic events over Russia since 1908, when an asteroid was blamed for a massive blast in Siberia.

Nasa estimated that the amount of energy released when the meteor crashed into the Earth's atmosphere was about 20 times more than the force of the Hiroshima nuclear bomb.

"We would expect an event of this magnitude to occur once every 100 years on average," said Paul Chodas of Nasa's Near-Earth Object Programme Office.

The drama happened just hours before an asteroid whizzed safely past the Earth at an unprecedented distance of 17,200 miles.

This is closer than some distant satellites and set alarm bells ringing in some Russian circles about the need for joint global action to protect Earth from space.

The Russian parliament's foreign affairs committee chief Alexei Pushkov wrote on Twitter: "Instead of fighting on Earth, people should be creating a joint system of asteroid defence."