A Russian plane has disappeared from radar just minutes after take-off from the Black Sea resort of Sochi, Russian media say.
They are quoting a source at the emergency ministry as saying the missing aircraft is a Tu-154.
Between 70 and 100 people are reported to be on board the plane.
Unconfirmed reports say the aircraft belongs to the defence ministry, flying to Syria’s Latakia province. Russian officials have so far made no comment.
Interfax news agency reports quoted a source as saying that the plane disappeared from radar 20 minutes after take-off at 05:20 local time (02:20 GMT).
The aircraft went missing as it was manoeuvring over Russia’s territorial waters, the source added.
Reports suggest a military music band and reporters were among those on board the aircraft.
A search operation is now under way, Russia’s state-run Rossiya24 TV channel reports.
UPDATE 2: Aircraft debris has been found about 6 kilometers off the coast of Sochi, the TASS news agency reports, citing sources.
UPDATE 1: An oil slick has been spotted just about 6 kilometers off the coast of Sochi and rescue workers believe the aircraft may have crashed there, but debris has not yet been seen, a source has told Interfax.