Russian President Vladimir Putin has instructed Prime Minister Dmitry Medvedev to lead the probe into the Tu-154 military plane crash over the Black Sea on Sunday (25 December). Rescuers have reportedly recovered five bodies of the 92 people on board the plane, with no sign of survivors as yet.

Transport Minister Maxim Sokolov did not rule out a terror attack when asked, saying that investigators were looking into every possible reason. Viktor Ozerov, chairman of the Federation Council Committee on Defence and Security initially ruled out the possibility of a terror attack.

The defence ministry has released a list of the passengers and crew members on board the doomed flight. Putin has declared a national day of mourning for 26 December, and expressed his "deepest condolences" to the families of the crash victims.

The Russian defence ministry said in a statement earlier that a ministerial commission led by Transport Minister Maxim Sokolov has already left for the resort city of Sochi to probe the crash, which is believed to have been caused by a technical failure or pilot error.

Among the passengers were about 65 members of Russian military choir Alexandrov Ensemblem, journalists, and charity workers. The flight was bound for Latakia in Syria. It crashed about seven minutes after take-off from Sochi Airport.

Medvedev said: "This terrible tragedy has claimed the lives of people, full of strength and plans. Journalists, soldiers and musicians of the famous Alexandrov ensemble are among the victims. They flew to Syria with a very good and peaceful mission. This bereavement is impossible to accept ... it is an irreparable loss. Millions of people share this tragedy."

Well-known Russian charity leader Elizaveta Glinka was among the passengers of the crashed aircraft. The head of the presidential Human Rights Council Mikhail Fedotov, who was scheduled to fly with Glinka in the same flight, said: "I knew that she was going there. Moreover, we were going to fly together, but unfortunately, only she was allowed to go. And I know that she went there to bring medicines. This is not a tour, not a pleasure trip, she was carrying medication to a university hospital in Latakia."

The Russian Federal Service for Employment and Labour Relations has sent its representatives to Sochi to investigate the crash, with the ministry assuring the affected families of insurance payments.