Official: 'No Explosion' in Deadly Russian Plane Crash A Russian official blamed the crash on a combination of factors.

 -- Investigators into the crash of a Russian military plane that killed 92 people heading from the Russian city of Sochi to Syria have determined that there was no explosion or fire on board, officials said on Thursday.

Lt. Gen. Sergei Bainetov said Thursday that "we have come to conclusion that there was no explosion on board," according to the Associated Press.

Bainetov added that investigators haven't yet ruled out the possibility of a terror attack.

The Russian military Tu-154 plane crashed just minutes after takeoff in good weather over the Black Sea. The passengers included a well-known military choir, the Alexandrov Ensemble, that was headed to Syria to perform at a New Year's concert at a Russian air base in the port city of Latakia.

Nine Russian journalists and a doctor famous for her work in war zones also died in the crash.

Officials also said on Thursday that the active search phase of the crash investigation had ended, with three black boxes as well as 20 bodies and nearly all of the remains of those on board recovered.

"Tentatively, the bodies of 20 people and the remains of almost all of the victims have been lifted to the surface. A DNA test will be required in order to identify the majority of the victims of the tragedy," a source in Russia's Emergency Situations Ministry said.

Military aviation experts have started to decode information from the plane's two flight data recorders, while the decoding of the third black box will begin in the afternoon on Thursday, the source said.

"The tape from the third recorder was subject to mechanical exposure and exposure to seawater. However, the main information can be received from it," according to the source, who said that the two other black boxes are in good condition.

"Tentatively, information that has been received from them tells about the circumstances of the catastrophe and indirectly points to a combination of factors that potentially could have led to the catastrophe," the source said.

ABC News' Tanya Stukalova and the Associated Press contributed to this report.