UPDATE: 1:51 a.m. EDT — A body of a passenger of the crashed Tu-154 plane has been found about 4 miles from Sochi coastline, Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said Sunday. There is no word on other survivors of the plane belonging to the Russian defense ministry.

The country’s investigative committee has opened a criminal case into the crash of the plane, which disappeared from radar early Sunday after taking off from Sochi. The investigation has been launched into "the violation of rules of flights safety or preparation for them," Svetlana Petrenko, the committee spokeswoman, told Tass news agency.

Personal belongings of those on board were reportedly found off the Sochi coast. "There were 91 people onboard, 68 of them are musicians of the Alexandrov Ensemble, nine mass media representatives, six accompanying people and eight crew members," a source with regional emergencies services told Tass.

UPDATE: 1:20 a.m. EST — The missing Tu-154 plane of the Russian defense ministry crashed over the Black Sea on Sunday, Interfax news agency reported citing an unidentified source. The crash site has been located by rescue personnel, the report added.

Debris and chassis of the plane have been found about 4 miles from the Black Sea coast, a source in the regional law enforcement services told Tass news agency. "The parts of the plane and undercarriage, and also an oily spot have been found some six kilometers from the coast," the source said.

UPDATE: 12:50 a.m. EST — The Russian defense ministry's Tu-154 plane likely disappeared early Sunday due to a technical fault or human error, a military source told RIA Novosti news agency.

The plane was heading toward Latakia province in western Syria, bordering Turkey, for New Year’s concert, according to RT. Journalists from Russian broadcasters Channel 1 and Zvezda were on board the aircraft.

UPDATE: 12:29 a.m. EST —The missing Tu-154 plane of the Russian defense ministry had arrived in Sochi for refueling, a source told RIA Novosti news agency.

“According to preliminary data, the missing Tu-154 arrived in Sochi from Chkalovsky airfield near Moscow for refueling. It is likely that it crashed in the mountainous area of the Krasnodar region,” the source reportedly said.

Those on board the plane included journalists, military officials and musicians from Alexandrov Ensemble — an official army choir of the Russian armed forces, according to Sputnik. The plane went off radar while it was maneuvering in the Russian airspace over Black Sea after its takeoff from Sochi.

The plane was carrying 91 people, including 83 passengers and eight crew members, according to the Russian defense ministry.

UPDATE: 12:03 a.m. EST — The Russian defense ministry’s Tu-154 plane disappeared from radar “approximately 20 minutes after takeoff” from Sochi, a source told RIA Novosti news agency. The plane departed at 5:20 a.m., local time, (9:20 p.m. EST Saturday) and failed to check in with the tower at 5:40 a.m., the report added. Musicians and journalists were on board the plane, according to Tass.

Original story:

The Russian defense ministry’s Tupolev Tu-154 plane has disappeared from radar after taking off from Sochi city in the southwestern part of the country, Russian media reported Sunday.

"Tu-154 [aircraft] of the Defense Ministry departed from Sochi and disappeared from radars after some time. Its search is currently organized," a source from the regional emergency services told Tass news agency.

There are conflicting reports about the number of people on board the plane. RIA Novosti news agency reported that about 70 people were there, while the regional emergency services source told Tass that there were approximately 100 people on board the plane.

The plane was on its way to Latakia province in Syria, according to reports.

This is a developing story.