There appeared to be no survivors, and those on board included members of Russia's world-famous army choir.
The cause of the crash wasn't immediately known, but some experts pointed at a terror attack as a possible reason, a scenario rejected by Russian officials.
A total of 84 passengers and eight crew members were on the Tu-154 plane when it disappeared from radar two minutes after taking off in good weather.
The plane belonged to the Defence Ministry and was taking the Alexandrov Ensemble to a New Year's concert at Hemeimeem air base in Syria's coastal province of Latakia.
More From This Section
President Vladimir Putin went on television to declare tomorrow a nationwide day of mourning.
"We will conduct a thorough investigation into the reasons and will do everything to support the victims' families," Putin said.
More than 3,000 people including dozens of divers worked from 27 ships and several helicopters to search the undersea crash site, according to the Defence Ministry. Drones were also flown over to help spot bodies and debris.
Russian Defence Ministry spokesman Maj Gen. Igor Konashenkov said 10 bodies had been recovered so far "No survivors are seen," Konashenkov said.
Magomed Tolboyev, a decorated Russian test pilot, said the circumstances of the crash indicated that all people on board have died.
"There is no chance to survive in such situation," he said, according to the Interfax news agency. "The plane gets instantly blown into pieces."
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. The plane that crashed was built in 1983, and underwent repairs in 2014, according to the Defence Ministry.
He said he believes it could not have been a terror attack because the plane was operated by the Russian military.
"I totally exclude" the idea of an attack bringing down the plane, he said according to the state-run RIA Novosti news agency.