Local media reported that the incident occurred at 5 a.m. local time [02:00 GMT]. The bus was en route from the resort of Alanya to the town of Pamukkale when it veered off the road into the Aksu River 15 meters below.
The Russian consul in Antalya said 25 Russians were also injured in the crash.
Emergency services were working at the scene of the accident, taking the injured from the bus and providing them with medical aid.
The Turkish NTV channel said the death toll may increase as the bus took the roadside barrier with it to the bottom of the ravine, where it had “turned into a pile of metal.”
According to the latest information, a six-kilometer traffic jam has developed at the scene of the accident.
Preliminary investigations suggest the driver fell asleep at the wheel.