'No explosion' on board crashed Russian plane: military

Moscow: Russian officials probing the crash of a Syria-bound military plane said Thursday that there was no explosion on board, but equipment was functioning abnormally when it plunged into the Black Sea.

"There was no explosion on board, I can say that for certain," said Sergei Bainetov, head of flight safety for the Russian airforce. "But an act of terror is not necessarily an explosion, so we are not discarding this version."

Transport Minister Maxim Sokolov said the probe has established that the plane was not working normally but will not issue any conclusions before January, cautioning journalists not to jump on any theories.

"It is obvious that the equipment was functioning abnormally. Why that happened is up to experts to work out," he said at a joint press conference on the crash which killed all 92 on board, including scores of performers from a feted Red Army Choir troupe.

The Soviet-era Tu-154 plane went down shortly after takeoff from the Sochi airport Sunday morning, after stopping to refuel on its way to Syria.

The military ensemble was due to give a concert to Russian soldiers at the Hmeimim base, Moscow's main outpost for its bombing campaign in support of President Bashar al-Assad.

Bainetov said that the Tu-154, which is not used by commercial airlines, has been grounded by the air force "until the first conclusions" are made about the crash.

Sokolov said that the "main phase" of the major search operation for plane debris mounted off the coast of the southern city has finished.

"At this time, everything that has to do with the plane's crash has been brought to surface," he said.

So far only 19 bodies and some 230 body parts have been discovered, Sokolov said.