Russian officials say they have recovered a second black box from the military passenger jet that crashed in the Black Sea en route to Syria on December 25.
The Defense Ministry said on December 28 that a flight-data recorder from the Tu-154 plane was found on the seabed near the coastal city of Sochi, one day after the first black box was retrieved.
All 92 passengers and crew were killed when the Russian Defense Ministry Tu-154 crashed minutes after taking off from the coastal city of Sochi, where it had stopped to refuel after flying from Moscow.
Russian authorities said earlier on December 28 that salvage workers have now recovered the bodies of 15 people from the plane, along with more than 200 body parts and various fragments of the plane.
The human remains are being sent to Moscow for DNA identification.
More than 60 of the victims were members of the Russian military's famed Aleksandrov song-and-dance ensemble, also known as the Red Army Choir, which was to perform for Russian servicemen deployed in Syria to support President Bashar al-Assad's government in the civil war there.
Nine Russian TV journalists and prominent charity worker Yelizaveta Glinka, or Doctor Liza, were also killed.
The cause of the crash has not been determined, but Russian officials say they do not believe it was terrorism.
State news agency TASS cited unnamed security officials as saying on December 28 that divers were focusing on the submerged tail section of the aircraft, which they said contains two flight-data recorders.
Authorities said a separate recorder was recovered earlier and was being examined at a military facility outside Moscow.
While earlier reports identified the device as a data recorder, TASS and other Russian news outlets now say it is the cockpit voice recorder.
On December 27, online publication life.ru published what it said was a transcript of remarks in the cockpit shortly before the crash, with one crew member yelling about a problem with the plane’s flaps and one saying: "Commander, we're falling!"
RFE/RL could not verify the report by life.ru, which is known to have close connections with Russian security agencies.
Russian transport and security officials have said there are no indications the plane was brought down by a bomb or any other kind of terrorist attack.
According to Russian media, the Federal Security Service says possible causes of the crash include pilot error, a technical problem, a foreign object getting caught in an engine, and poor-quality fuel. But several factors -- including the fact that the crew did not report any problem to air-traffic controllers, and the large number of fragments and body parts found in the sea -- have sparked speculation about the potential cause.