Russia has grounded all Tupolev-154 planes until it understands why one of the ageing Soviet planes crashed into the Black Sea on Sunday, killing all 92 on board, the Interfax news agency cited an unnamed source as saying on Tuesday.

Russian news agencies cited the Defence Ministry earlier on Tuesday as saying that authorities had found one of the downed plane's flight recorders. bla

One of the priority causes that might have caused the crash is the penetration of foreign objects in the engine, informs TASS.

According to the FSB’s latest conclusions, no evidence has been found linking the crash to terrorism.

A Tu-154 plane from Russia’s Defense Ministry crashed in the early morning hours of December 25 shortly after taking off from the Black Sea resort of Sochi.

There were 92 people on board the aircraft, including eight crew members and 84 passengers that lost their lives in the plane disaster. Among those on the fatal flight was the Executive Director of the Spravedlivaya Pomoshch (Fair Aid) charity fund, Elizaveta Glinka, as well as military servicemen and nine reporters from Russia's Channel One, Zvezda and NTV networks. da

The plane was also carrying members of the world-renowned Alexandrov Ensemble, an official army choir of the Russian Armed Forces. The ensemble was on its way to celebrate New Year’s Eve with Russia’s Aerospace Forces at the Hmeymim air base in Syria.