A big rescue and clean-up operation involving more than 9,000 workers is going on in the Ural mountains following Friday’s meteor strike, Russia’s emergencies ministry says.
President Vladimir Putin ordered the operation to help some 1,200 people who were injured, including 200 children, mostly by shattered glass.
The shockwave damaged an estimated 200,000 sq m (50 acres) of windows.
Russian officials put the cost of the damage at about 1bn roubles ($33m).
Power of small atomic weapon
A fireball had streaked through the sky on Friday, followed by loud bangs.
A large fragment reportedly landed in a lake near Chebarkul, a town in the Chelyabinsk region. A Russian army spokesman said a crater 6m (20ft) wide had been found there.
An emergencies ministry spokeswoman said a group of six divers would inspect the waters for the presence of pieces of a meteorite.
Emergencies Minister Vladimir Puchkov toured Chelyabinsk city on Saturday to assess the damage.
He said: “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.”
More than 9,000 people are working to clear up the damage in the Chelyabinsk region. Most are locals, but some 1,800 people came from neighbouring regions.
Mr Putin said he had thanked God that no big fragments of the 10-tonne meteor – which was thought to be made of iron and travelling at some 30 km (19 miles) per second – had fallen in populated areas.
It had entered the Earth’s atmosphere and broke apart 30-50 km (20-30 miles) above ground, according to Russia’s Academy of Sciences, releasing several kilotons of energy – the equivalent of a small atomic weapon.
Mr Puchkov said there was no confirmation yet that any fragments had been found.
The emergencies ministry urged calm, saying background radiation levels were normal after what it described as a “meteorite shower in the form of fireballs”.
Some 50 people remain in hospital for treatment – mainly for cuts and bruises from shattered glass.
‘Little explosions’
The Chelyabinsk region, about 1,500km east of Moscow, is home to many factories, a nuclear power plant and the Mayak atomic waste storage and treatment centre.
The shockwave blew out windows in more than 4,000 buildings in the region.
Regional governor Mikhail Yurevich said damage was estimated at 1bn roubles but dismissed as a “journalistic spoof” reports in Russian media that people had deliberately shattered windows to claim on meteorite-related insurance.
Many children were in classrooms when the meteor fell at around 09:20 (03:20 GMT).
Video posted online showed frightened, screaming youngsters at one Chelyabinsk school, where corridors were littered with broken glass.
Chelyabinsk resident Sergei Serskov told BBC News the city had felt like a “war zone” for 20 to 30 minutes.
“I was in the office when suddenly I saw a really bright flash in the window in front of me,” he said.