At least 23 people died and 11 were injured when a bus carrying Turkish tourists plunged off a road near the southwestern sea resort of Marmaris.

Governor of Mugla province Amir Cicek said the bus was carrying about 40 people, many of whom were women.

His deputy, Kamil Koten, said the bus plunged through a crash barrier and fell 15m on to a lower road, smashing a car with its three occupants.

"If we count these three deaths, the number of the dead rises to 23," the state-run Anadolu news agency quoted him as saying.

The crash happened on a hilly road and the bus plunged into a precipice after smashing through the crash barrier.

An investigation is under way.

Other media outlets reported that the bus left from the western city of Izmir carrying only women and children who were on a trip for Mothers' Day, celebrated in Turkey tomorrow.

Marmaris is one of the country's main resorts on the Mediterranean, and a popular weekend destination for many Turks as temperatures climb.