Divers working at a Russian lake have recovered a half-tonne chunk of the space rock that exploded over Chelyabinsk earlier this year.

The object plunged into Lake Chebarkul in central Russia on 15 February, leaving a 6m-wide hole in the ice.

Scientists say that it is the largest fragment of the meteorite yet found.

More than 1,000 people were injured when a 17m, 10,000-tonne space rock burned up over Central Russia, breaking windows and rocking buildings.