MOSCOW, December 25. /TASS/. A terrorist attack is not considered as a key theory of the Tu-154 plane crash near the Black Sea resort city of Sochi, a source in Russian security services said on Sunday.

"The Tu-154 took off from the Chkalovsky airfield where the passengers and their luggage were thoroughly checked," the source said. "It was planned to make a stopover in Mozdok for refueling but due to unfavorable weather conditions it was finally made in Adler. So, no one knew beforehand that the plane will make a stopover in Sochi."

The source said that upon arrival to Sochi, the plane was taken under enhanced guard. "Only two border and one customs officers got inside the plane and the navigator pilot got out of the plane to control the fueling process. No meals were delivered aboard. Fueling was carried out by regular personnel," he added.

Thus, according to the source, there is no evidence of a possible terrorist attack and neither the investigators nor security service consider this theory as the key one."

A Tu-154 plane from Russia’s Ministry of Defense vanished from radar screens at 05.40 a.m. Moscow time (02.40 a.m. GMT) shortly after taking off from the Black Sea resort of Sochi.

According to the latest information, there were 92 people on board the aircraft, consisting of 8 crew members and 84 passengers. Among them was the Executive Director of the Fair Aid charity fund, Elizaveta Glinka, better known to the Russian public as Dr. Liza, as well as servicemen and reporters, including from Channel One, Zvezda and NTV.

The plane was also carrying more than 60 members of the famous Alexandrov ensemble, an official army choir of the Russian armed forces, who set off to celebrate the New Year with the air group of Russia’s Aerospace Forces at the Hmeymim air base in Syria. The choir’s conductor Valery Khalilov was also on the list of passengers.

The Defense Ministry said that fragments of the Tu-154 had been found 1.5 km off the coast of Sochi at the depth of 50-70 meters. Eleven bodies of the crash victims have been found. It seems no one has survived. A search operation is underway.

The Russian Investigative Committee opened a criminal case on charges of violations of flight safety rules resulting in human deaths.