"During the launch of a Dnepr carrier rocket, which was to have orbited 18 Russian and foreign-made [mini-] satellites, the rocket's first stage engine experienced an emergency shutdown," said Igor Panarin, the Federal Space Agency's press secretary. "This is the agency's official viewpoint."
The Dnepr, a civilian version of the heavy R-36M2 Voyevoda (SS-18 Satan) intercontinental ballistic missile, was launched around midnight (8 p.m. GMT Wednesday).
Earlier today, it was reported that there had been no casualties or environmental damage and that a special investigation commission had launched a probe into the accident.
Panarin also said that the exact location where the rocket hit the ground was yet to be established.
"A search started in the morning, but the rocket has not been discovered yet," he said. "The rocket most likely fell in an uninhabited area, which will complicate the search."
Russia has been using converted ballistic missiles to launch satellites into orbit since 1999. The Dnepr, which was seen as a highly reliable carrier rocket, has a lift-off weight of about 250 metric tons and can carry a satellite payload of up to 3.7 tons to orbits at an altitude of 300-900 kilometers (185-560 miles).