The death toll rose from 56 to 57 after a re-examination of the passenger manifest. The initial toll omitted a baby among the passengers of the aircraft.

Fifty passengers and seven crew were on board the Istanbul to Isparta flight.

The AtlasJet plane disappeared off radar screens shortly after the pilot told the control tower he was descending to land in the mountainous town of Isparta.

One official said the site of the crash, about 12 kilometres from the airport, was not on the plane's route, suggesting it had veered off course.

The weather was fine and officials say visibility would not have been a problem.

The pilot did not send a distress signal.

The investigation team "recovered the CVR and FDR devices, known as black boxes, and are pursuing their investigation of the crash site," Turkey's civil aviation authority said in a statement.

The data in the cockpit voice recorder and the flight data recorder is expected to shed light on the cause of the crash.

The plane, a MacDonnell Douglas 83 operated by the low-fare AtlasJet carrier, disappeared from radar screens around 01:36am local time.

The airline's chief executive, Tuncay Doganer, says search and rescue teams are scouring through the debris that is scattered around the area.

"The helicopter has just landed near the wreckage and the teams have arrived there," he said.

"Unfortunately we have no surviving citizens." © 2007 Australian Broadcasting Corporation