A Russian military Tu-154 aircraft crashed into the Black Sea on Sunday, presumably killing all 92 people aboard, said the Russian Defense Ministry.

Photo taken on Dec. 25, 2016 shows the rescue operation on the Black Sea coast at the crash site of Russian Defense Ministry's Tu-154 aircraft. Several bodies have been found at the crash site of a missing Russian military Tu-154 aircraft in the Black Sea, Russian media reported Sunday, citing the Defense Ministry press service. [Xinhua]

The ill-fated plane, en route to Russia's Hmeimim air base in the Syrian port city of Latakia, vanished from the radar screens shortly after takeoff from an airfield in the Black Sea resort city of Sochi at 5:40 a.m. Moscow Time (0240 GMT).

Several bodies of the victims have been recovered at the crash site. Fragments of the aircraft have been discovered in 1.5 km from the Black Sea shore of Sochi at a depth of 50-70 meters.

Over 3,000 people and dozens of ships have been deployed in a search and rescue operation led by Russian Defense Minister Sergei Shoigu, the ministry's press service said.

More than 200 policemen have also been mobilized in the mission, according to the local administration of the Russian Interior Ministry.

The federal Investigative Committee has launched a criminal case over the crash. Based on preliminary information, the tragedy was caused by technical malfunction or pilot error, a law enforcement source was quoted by the RIA Novosti news agency as saying. However, the Defense Ministry said the Tu-154 aircraft was flown by an experienced first-class pilot.

The Interfax news agency quoted an emergency services source as saying that the possibility of a terror attack has been virtually ruled out.

Live TV broadcast showed the weather was sunny at the time of the accident.

According to RIA Novosti, the Tu-154 was built in 1983 and has spent 6,689 hours in flight, with the most recent technical maintenance conducted in September 2016.

The Defense Ministry confirmed that a total of 92 people -- 84 passengers and eight crew members -- were aboard the plane.

Among the passengers were 64 members of the Alexandrov Ensemble, a renowned choir of the Russian Armed Forces, as well as nine Russian journalists. They were heading to the air base for New Year celebrations.

Russian President Vladimir Putin declared Dec. 26 a nationwide day of mourning, and promised a thorough investigation.

Russian TV channels, including the Zvezda, the NTV and Channel One, have named their journalists aboard the Tu-154 plane.

Established in 1928, the Alexandrov Ensemble is widely recognized as the oldest and biggest choir of the Russian military.

The Tu-154 is a three-engine medium-range airliner produced by Tupolev. It is one of the fastest civilian aircraft in use and has been widely used in extreme Arctic conditions.

Sunday's crash was the second accident in less than one week concerning Russian planes. On Monday, an Il-18 aircraft crash-landed near the Tiksi airfield in Russia's Far Eastern Sakha Republic, injuring 16 people.