At least twenty-nine people, mostly German tourists, have died and a further 27 have been injured after a tourist bus overturned on the Portuguese island of Madeira, local media have reported.

A battered white bus on its side surrounded by firefighters could be seen in photos published by Portuguese media, while SIC Television said there were 19 ambulances at the scene following the accident, which occurred around 5.30pm GMT.

Filipe Sousa, the mayor of Caniço – a coastal town in the south of the island, which lies about 600 miles south-west of mainland Portugal – told SIC: “I have no words to describe what happened. I cannot face the suffering of these people.” Sousa added that the victims included 17 women and 11 men.

The coach was reportedly carrying 55 passengers when it veered off a road on a bend east of the capital, Funchal, before rolling down a steep hillside, Sousa said. The Portuguese guide and driver reportedly survived the accident, and they along with the other wounded people were taken to hospital in Funchal.

A spokeswoman for the hospital told German newspaper Bild: “We currently have our hands full. We have many injured people from the bus accident here. The ambulances drove them from Santa Cruz to us. Many are very badly injured.”

Portuguese prime minister Antonio Costa said in a tweet that he had sent his condolences to the German chancellor, Angela Merkel. “I learned of this tragic accident in Madeira with deep sorrow,” he said.

Merkel’s spokesman Steffen Seibert said “terrible news is reaching us from Madeira” and that “we are in deepest sorrow over all those who lost their lives in the bus crash.” He added: “Our thoughts are with the injured.”

Germany’s foreign ministry said its embassy in Portugal’s capital, Lisbon, was in contact with local authorities in Madeira. Seibert said the government has set up a telephone hotline for people worried about family members.

It was not clear whether the fatalities were confined to the bus passengers, and authorities are investigating the possible cause. Locals reported that the weather was fine at the time of the accident, which happened in daylight.

A UK Foreign and Commonwealth Office spokesman said: “We are seeking information from the authorities in Portugal about a bus crash in Madeira, and are ready to support any British people who require assistance.”

The Portuguese president Marcelo Rebelo de Sousa had intended to travel to Madeira on Wednesday evening following the crash, but it was reported that the aircraft he uses could be required to bring injured people to the mainland and therefore he has cancelled the trip. “This is a moment of pain, but also of solidarity,” Sousa told SIC.

Five Italian tourists died in São Vicente, on the northern coast of Madeira, in a fatal bus crash in 2005.