MOSCOW (AFP) - Russian scientists said Monday they had discovered over 50 fragments of the meteor that struck the Urals last week, creating a shockwave that injured 1,200 people and damaged thousands of homes.

The giant piece of space rock streaked spectacularly over the central Russian city of Chelyabinsk on Friday before exploding with the force of 30 of the nuclear bombs dropped on the Japanese city of Hiroshima during World War II.

There was initial disappointment when Russian emergency ministry workers who scoured a lake where at least some of the fragments were believed to have fallen were unable to find anything in their initial search over the weekend.

But members of the Russian Academy of Sciences who conducted chemical tests on some unusual rock formations they found on Sunday said the pieces had come from outer space.

“We confirm that the particles of a substance found by our expedition near Lake Chebarkul really do have the composition of a meteorite,” RIA Novosti quoted Russian Academy of Sciences member Viktor Grokhovsky.

Grokhovsky’s Urals Federal University separately posted a statement on its website that featured a photograph of a person holding a tiny piece of a black shiny rock between his index finger and thumb.

“This meteorite belongs to the class of regular chondrites,” the university statement said, referring to specific term for a meteorite that contains small mineral granules.

Grokhovsky said the rock in question - one of a set of 53 that measure no more than a couple of centimetres (less than an inch) in length - was composed in part of iron as well as chrysolite and sulfite.

The meteor’s shockwave blew out the windows of nearly 5,000 buildings and left 40 people - including three children - still recovering in hospital Sunday with cuts and more serious injuries.

About 24,000 emergency workers and volunteers spent the weekend replacing smashed windows in time for the resumption of school classes and work on Monday.

“The southern Urals are gradually returning to the usual rhythm of things,” Chelyabinsk region governor Mikhail Yurevich said in a statement that announced the opening of the region’s elementary schools.

But the elusive meteorites - meteor fragments that have hit Earth - have generated almost as much attention as the enormous repair and restoration work.