Russian authorities have found a flight recorder in the wreckage of a military plane that crashed into the Black Sea on Sunday, killing all 92 on board, Russian agencies cited the Defence Ministry as saying on Tuesday.
The recorder, one of several reported to be on board, contains information which could help investigators identify the cause of the crash.
It will be sent to a Defence Ministry facility in Moscow for analysis, the ministry was cited as saying.
Investigators have so far said that pilot error or a technical fault were likely to have caused the Defence Ministry TU-154 to crash into the sea.
Russia has decided to ground all Tupolev-154 planes until it understands why one of the ageing Soviet planes crashed into the Black Sea on Sunday.
The plane was carrying dozens of Red Army Choir singers and dancers to Syria to entertain Russian troops in the run-up to the New Year, as well as other passengers.
The Defence Ministry said search and rescue teams have so far recovered 12 bodies and 156 body fragments, news agencies reported.
The Interfax news agency, citing a law enforcement source, said a second flight recorder had also been found in the wreckage, but not yet raised to the surface.