It would have shattered about 30-50 km above ground, with most of the meteor burning up.
Russian Army units found three meteorite debris impact sites, two of which are in an area near Chebarkul Lake, west of Chelyabinsk. The third site was found some 80 km further to the northwest, near the town of Zlatoust.
The Russian army has joined the rescue operation. Army units are searching for meteorite debris in several places in Chelyabinsk region and in the neighbouring Tyumen region.
The Emergency Ministry reported that 20,000 rescue workers are operating in the region. Three aircraft were deployed to survey the area and locate other possible impact locations.
Radiation, chemical and biological protection units have been put on high alert in the area. As the explosion has occurred several kilometres above ground, a large ground area has to be thoroughly checked for radiation and other threats.