They two satellites have been identified as Cosmos 2251 and Iridium 33.
Cosmos 2251
USSPACECOM Catalog No.: 22675
International Designation Code: 1993-036A
Satellite Details Orbit: 767 x 803 km, Inclination: 74.0°
Launch Date (UTC): June 16, 1993 (0417 UTC)
Mission: Russian Strela-2M military store-dump communications satellite (non-operational)
Launch Site: Site 132/1 at the Plesetsk Cosmodrome
http://www.astronautix.com/craft/strela2m.htm
Iridium 33 (Also called Iridium SV033)
USSPACECOM Catalog No.: 24946
International Designation Code: 1997-051C
Satellite Details Orbit: 783.0 x 798.2 km, Inclination: 86.4°
Launch date: September 14, 1997
Mission: LEO Communications Satellite
Launch site: Baikonur Cosmodrome, Kazakhstan
Launch vehicle: Proton K #252
http://www.astronautix.com/project/iridium.htm
"They collided at an altitude of 790 kilometers (491 miles) over northern Siberia Tuesday about noon Washington time," said Nicholas Johnson, NASA's chief scientist for orbital debris at the Johnson Space Center in Houston. "The U.S. space surveillance network detected a large number of debris from both objects."
Animated version of the collison at this link http://i39.tinypic.com/2vbk75z.gif (Courtesy of John Locker)Air Force Brig. Gen. Michael Carey, deputy director of global operations with U.S. Strategic Command, said initial radar tracking detected some 600 pieces of debris.
Iridium Satellite LLC operates a constellation of some 66 satellites, along with orbital spares, to support satellite telephone operations around the world. The spacecraft, which weigh about 1,485 pounds when fully fueled, are in orbits tilted 86.4 degrees to the equator at an altitude of about 485 miles. Ninety-five Iridium satellites were launched between 1997 and 2002 and several have failed over the years.
More on this story at
http://spaceflightnow.com/news/n0902/11iridium/
Here is an computer generated image of all the orbital debris in low earth orbit (LEO). LEO stands for low Earth orbit and is the region of space within 2,000 km of the Earth's surface. It is the most concentrated area for orbital debris. (Courtesy of the NASA Orbital Debris Program Office)
The last major spacecraft fragmentation and probably the most famous, was the intentional destruction of the Chinese Fengyun 1C weather satellite by a Chinese ASAT weapon. The current debris count from that incident now stands at 2,530 pieces.
