Russia has found the first flight recorder from a military plane that crashed into the Black Sea killing all 92 on board, the Defence Ministry said on Tuesday, amid unconfirmed reports that authorities had grounded all aircraft of the same type.
The recorder, one of several reported to be on board, contains information that could help investigators identify the cause of Sunday's crash, which killed dozens of Red Army Choir singers and dancers en route to Syria to entertain Russian troops in the run-up to the New Year.
Investigators have so far said that pilot error or a technical fault, rather than terrorism, are most likely to have caused the Defence Ministry Tupolev-154 to crash into the sea.
The first black box, which was founded by a remote-controlled underwater vehicle at a depth of around 17 metres and 1,600 metres from the resort of Sochi, will be sent to a Defence Ministry facility in Moscow for analysis.
"During the night during the (search operation) ... a further five fragments of the plane were found," the ministry said in a statement. They included pieces of fuselage and engine fragments.
The Interfax news agency cited an unnamed source as saying Russia had grounded all TU-154 planes until the cause of Sunday's crash became clear. There was no official confirmation of that.
TRT World's Julia Lyubova brings more from Moscow.