Russian investigators believe a technical malfunction, not sabotage or a bomb blast, is behind the crash of a Russian military Tu-154 plane that crashed into the Black Sea and killed 92 people on board, officials said Thursday.
The aircraft was carrying 84 passengers and eight crew members when it dropped off of the radar minutes after taking off from Russia around 5:25 a.m. local time.
"It is clear that there was a technical malfunction," transport minister Maxim Sokolov said during a briefing to reporters in Moscow, the Washington Post reported.
The official cause of the crash had yet to be determined, but officials said an explosion or a bomb had been ruled out.
"We arrived at the conclusion that there was no explosion aboard," Sergei Bainetov, head of the Russian armed forces' flight safety service, said at the briefing.
Bainetov said a recording of the pilots before the crash suggested there was an "emergency situation" before the crash, but did not go into detail.
On Tuesday, Russia's Investigative Committee said it was speaking with several witnesses of the crash, including one who filmed the jet's crash into the Black Sea, the Associated Press reported.
Samples of the plane's fuel tank were also taken as investigators look at the possibility that the crash was caused by bad fuel, officials said.
Russian officials also said Tuesday that the black box had been recovered a mile from shore. A second box was discovered on Wednesday. Russia's state TV aired footage which appeared to show rescuers taking a bright orange box ashore, AP reported.
The Alexandrov military choir was heading to a New Year's Eve concert at the Russian Hemeimeem air base in Syria's coastal province of Latakia at the time of the crash.
Nine Russian journalists, including a TV crew from Channel One, and a well-known doctor, famous for her work in war zones, were also among the passengers, the AP reported.
Emergency services found debris from the plane about 1.5 kilometers (less than one mile) from shore at a depth of 50 to 70 meters (165 to 230 feet).
"No survivors have been spotted," Ministry spokesman Major General Igor Konashenkov said.
At least 10 bodies have been pulled from the waters, the defense ministry said. On Monday, large fragments of the destroyed plane were pulled from the Black Sea, AP reported. About 45 ships and 135 divers are scouring the area for further bodies and debris, part of a massive rescue operation involving almost 2,000 people in total.
In Moscow, mourners have been leaving flowers and lighting candles outside the choir's official building. Monday was observed as a national day of mourning.
"First of all, I would like to express my most heartfelt condolences to the families of our citizens killed," Putin said in comments broadcast by the Kremlin.
"The government has been instructed to set up a commission to be headed by the transport minister," he added. "A thorough investigation will be conducted to determine the cause of the plane crash and every effort made to provide support to the families of the victims."