Russia's Defense Ministry said Tuesday search teams have found the main flight data recorder from a military passenger plane that crashed over the weekend in the Black Sea.
Russian news agencies said the device would be delivered to Moscow for analysis, as investigators try to figure out what caused the crash.
Late Tuesday, media reports quoted the Russian Interfax news agency as saying the second black box had been located but not recovered. Interfax also reported Tuesday that all models of the aircraft involved in the crash had been grounded.
Officials say that terrorism has not been ruled out in Sunday's crash, but that it is extremely unlikely.
All 92 people on board the plane were killed. The Defense Ministry said that as of early Tuesday, search crews had found 12 bodies and many more body parts.
On Monday, the Emergency Situations Ministry reported 45 ships and 135 divers from across Russia found parts of the jet about 1.5 kilometers from shore and 25 meters under the sea.
Russian media reports speculated on possible causes such as a technical problem, human error, or that the plane may have been overloaded.
“The Tu-154 has not been manufactured for quite a while and the Ministry of Defense was practically the only user of the aircraft,” says Maxim Pyadushkin, managing director of Air Transport Observer magazine. “But the Defense Ministry stated that it had passed through the capital maintenance. That means its condition was under control. We can't so far state whether there were some technical issues. The results of the investigation will show.”
Day of mourning
Russia held a national day of mourning Monday to honor the people who died when the 33-year-old Tu-154 aircraft crashed into the Black Sea on its way from Sochi to a Russian military base in Syria.
Among the victims were 68 members of the Alexandrov Ensemble, a military choir, orchestra and dance group that was to give a New Year’s performance for Russian airmen at the military base near Latakia.
Mourners in Moscow lit candles and left flowers outside a concert hall where the group had performed.
A Russian video news agency showed mourners gathered on the Black Sea coast laying flowers, lighting candles, dropping cloves into the water during a vigil on the Grafskaya piers in Sevastopol to honor the victims of the disaster.
Vladimir Kuznetsov, a former member of the Alexandrov Ensemble, came to pay his respects to crash victims.
"I know all of them. I cannot believe it, can't collect myself," Kuznetsov told AFP.
"They knew us all over the world, we went everywhere," he said of the group while holding a candle in a plastic cup.
Russia state television cancelled entertainment programs and broadcast black and white pictures of the victims.
Nine Russian journalists and a well-known human rights activist, Elizaveta Glinka, known as "Dr. Liza," were among those killed. Glinka was said to be taking medical supplies to help victims of the nearly six-year Syrian conflict.
While Russian officials downplay the possibility of a terrorist attack, there are concerns that Russia’s intervention in Syria has made it more a target for extremists.
Russia’s ambassador to Turkey was assassinated last Tuesday in Ankara by a police officer apparently motivated by the Russia-backed assault on Aleppo by Syrian forces.
Russia has defended its backing Syrian forces as a fight against terrorism, while critics say rebels opposed to Syrian President Bashar-al Assad were the main target.
Some Russian media reports said victims of Sunday’s crash were found in lifejackets, indicating that a sudden explosion from a bomb was unlikely.
“A version about a terrorist act is so far a mere assumption,” Pyadushkin said. “Only investigation could provide some proof. One would like to hope that the Russian aviation commission together with the military could conduct an efficient investigation of the catastrophe.”
Chris Hannas contributed to this report.