At least 23 people have died after a bus carrying women and children plunged off a cliff near the Turkish resort of Marmaris.

“Sadly, we have had 20 fatalities and 11 other seriously injured,” said Amir Çiçek, the governor of Muğla province, calling it a “horrible accident”.

His deputy, Kamil Koten, said the bus crashed through a barrier and fell 15 metres (50 feet) on to a lower road, landing on a car with 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 accident occurred on Saturday near the Sakar pass, on a steep road filled with hairpin bends.

Çiçek told NTV television an investigation was under way. “The bus’s brakes may have malfunctioned,” he said.

The Turkish president, Recep Tayyip Erdoğan, currently on a visit to China, said he was “extremely pained” by the tragedy and has asked local authorities to take measures to ensure that “such tragedies” do not recur.

The Hurriyet newspaper quoted the mayor of Marmaris, Ali Acar, as saying there had been an “error by the driver” without giving further details.

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 this Sunday.