NOVOSIBIRSK, May 7 (RIA Novosti) - A group of Russian researchers looking for a meteorite that fell in January in the Altai Territory in southern Siberia has found an extraterrestrial substance which could be meteorite fragments, a coordinator said Monday.

"We have collected about 50 samples, and vitreous threads (traces of comet substance) were discovered in the first of them using a microscope," Vadim Chernobrov of Kosmopoisk (space search) said.

"We will reach the meteorite site in a few days, but rocks which are probably meteorite fragments have already been found," Chernobrov said.

He said only laboratory testing could establish the rocks' origin, adding that there were many volunteers involved in the operation from Moscow, Novosibirsk, Kostroma and local areas. He said all finds will be given to a museum.

Earlier, it was reported that January 10, local motorists and residents witnessed the impact of a fiery ball, which eventually ended in a loud sound resembling an explosion.

"Witnesses called us. This must have been a meteorite," a senior scientist from the Barnaul planetarium said.

Natalya Pavlova said that since a fallen meteorite was discovered in 1840, some 20 meteorites, including 4 in the 21st century, have been registered in the area.