MOSCOW (AP) -- A Russian plane headed to an air base in Syria with 92 people aboard, including members of the world-famous Russian army choir, crashed into the Black Sea on Sunday minutes after taking off from the city of Sochi, Russia's Defense Ministry said. There appeared to be no survivors.

President Vladimir Putin went on television to declare a nationwide day of mourning Monday.

By Sunday afternoon, rescue teams had already recovered several bodies from the site of the crash of the Tu-154, which belonged to the Defense Ministry and was taking the Alexandrov Ensemble to a New Year's concert at the Hemeimeem air base in Syria's coastal province of Latakia. Ships, helicopters, drones and divers searched the area for more victims.

A total of 84 passengers and eight crew members were on the plane when it disappeared from radars two minutes after taking off in good weather. Emergency crews found fragments about 1.5 kilometers from shore. There was no immediate word on the cause.

We will conduct a thorough investigation into the reasons and will do everything to support the victims' families, Putin said in a televised statement.

Viktor Ozerov, head of the defense affairs committee at the upper house of Russian parliament, said the crash could have been caused by a technical malfunction or a crew error, but he believes it could not have been terrorism because the plane was operated by the military.

I totally exclude the idea of an attack bringing down the plane, he said in remarks carried by state RIA Novosti news agency.

The passenger list released by the Defense Ministry included 64 members of the Alexandrov Ensemble, among them its leader, Valery Khalilov. The ensemble, often referred to as the Red Army choir, is the official choir of the Russian military and also includes a band and a dance company.

The choir sang Get Lucky at the opening of the 2014 Winter Olympics Russia hosted in Sochi, becoming an instant online sensation.

Losing such a great collective all at once is a great tragedy, Moscow city's culture department head Alexander Kibovsky said, according to RIA Novosti.

The military has repeatedly flown groups of Russian singers and artists to perform at Hemeimeem, which serves as the main hub for the Russian air campaign in Syria conducted since September 2015. New Year's is the main holiday for most Russians, and the Orthodox Christmas on Jan. 7 is also widely celebrated.

Also on board was Yelizaveta Glinka, a Russian doctor who has won wide acclaim for her charity work that included missions to war zones in eastern Ukraine and Syria. Her foundation said that Glinka was accompanying a shipment of medicines for a hospital in Syria.

Putin presented Glinka with an award earlier this month.

We never feel sure that we will come back alive, she said at the Kremlin award ceremony. But we are sure that kindness, compassion and charity are stronger than any weapon.

Nine Russian journalists from three Russian television stations were also among the passengers.

Defense Minister Sergei Shoigu was personally coordinating the rescue efforts, and Putin has received official reports on the incident.

Russian Prime Minister Dmitry Medvedev described the crash as a terrible tragedy.

The Tu-154 is a Soviet-built three-engine airliner designed in the late 1960s. More than 1,000 have been built, and they have been used extensively by carriers in Russia and worldwide.

In recent years, Russian airlines have replaced their Tu-154s with more modern planes, but the military and some other government agencies in Russia have continued to use them.

While noisy and fuel-guzzling by modern standards, the plane has been popular with crews that appreciate its maneuverability and ruggedness.

It's an excellent plane, which has proven its reliability during decades of service, veteran pilot Oleg Smirnov said in televised remarks.

The plane that crashed was built in 1983, and underwent repairs in 2014, according to the Defense Ministry.

In April 2010, a Tu-154 carrying Polish President Lech Kaczynski and 95 others crashed while trying to land at a sporadically used military airport in Smolensk in western Russia, killing everyone on board. Investigations by both Polish and Russian experts blamed pilot error in bad weather conditions, but Polish authorities have launched a new probe.