Russia’s Emergencies Ministry said the aircraft, a Boeing 737-800, crashed shortly before 4 am at the airport in Rostov at the end of a flight from Dubai.
The Ministry said the plane had to abandon an initial attempt to land and came down while making a repeat attempt.
The regional governor said most of the passengers on board were Russian and that weather was being considered as the cause of the crash.
A Russian transportation official said, however, that pilot error was another possible explanation.
A flight plan animation of the route taken by the ill-fated flight shows it made several loops while waiting to land.
Dubai-based Flydubai Airline confirmed that Flight 981 crashed on landing.
State news agency Tass reported that the Investigative Committee, the country’s top investigative agency, said preliminary information indicates the plane was landing when it hit the ground and broke into pieces about 950 kilometers south of Moscow.