Vladimir Putin has ordered an investigation after a Russian military plane carrying 92 people, including dozens of Red Army choristers, crashed into the Black Sea on its way to Syria. The Tupolev Tu-154 plane was carrying musicians from the famous Alexandrov military choir, as well as dancers, musicians and journalists, to a new year concert for troops in Syria. It crashed soon after taking off from the resort of Sochi on Sunday. In a statement, the Kremlin said that Putin expressed his "deepest condolences to the families and friends of those killed in the crash". He also ordered the prime minister, Dmitry Medvedev, to form a state commission to investigate the crash. It will determine whether safety breaches led to the crash. Russian agencies said all possible reasons for the crash were being examined, but investigators believed terrorism was unlikely. Russia's RIA news agency, citing an unidentified security source, said preliminary data indicated the plane had crashed because of a technical malfunction, Reuters reported. A total of 84 passengers and eight crew were on board when the plane dropped off radar shortly after take-off at 5:40am local time (0240 GMT) from Adler airport in Sochi, southern Russia. The plane had stopped off at Adler en route from Moscow to Syria. Russia's defence ministry said fragments of the plane, a Soviet-designed three-engine airliner, had been found by rescuers about 1.5km (one mile) from the shore in water 50-70 metres deep. There were no reports of survivors. An unnamed ministry source told Russian news agencies that those on board had almost no chance of surviving and that no life-rafts had been found. Interfax cited another unnamed source as saying the plane had not sent an SOS signal. Those on board included Russian servicemen and artists from the Russian military's official choir, the Alexandrov Ensemble, who were on their way to celebrate the upcoming New Year's Eve with air force personnel at the Khmeimim air base near Latakia in western Syria, the defence source told RIA. Defence ministry spokesman Major-General Igor Konashenkov said nine Russian reporters had also been on board, as well as military servicemen. The journalists were from state-controlled NTV and First Channel, as well as the army's channel Zvezda. "The search operation is continuing," said Konashenkov. "Four ships, five helicopters and a drone are working in the area," he said, saying a military commission had flown to Sochi to look into what happened. The Interfax news agency cited an unnamed source in the emergency services as saying about six bodies had already been recovered from the sea. According to the defence ministry's list of passengers, Elizaveta Glinka, a member of Putin's advisory human rights council, was on the plane. Known as Doctor Liza, she was a well-known public figure who had run a major humanitarian effort on the separatist side of the lines during the recent war in east Ukraine.