At least 14 people were killed and 35 others were injured when a tour bus crashed into a tree in Thailand.

The coach swerved off the highway and smashed into a tree along Petchkasem Road in Prachuap Khiri Khan province in the early hours of December 5.

The accident was reported to the district police station at around 1 am and emergency responders were sent to the scene.

The rescue crew and medics arrived and found the severely damaged bus with its front part split in two after ramming the tree. Inside the ruined vehicle were dozens of passengers trapped in the wreckage.

Rescuers pulled out 35 survivors and gave them first aid before transporting them to the Thap Sakae Hospital and Prachuap Khiri Khan Hospital for treatment, while at least 14 people had died in the horror crash.

Authorities said the bus, operated by Srisiam Tour Limited on the Bangkok-Nathawi route, had been transporting 46 passengers at the time.

It was bound for Songkhla province and had stopped at a restaurant before crashing near the Hat Wanakorn National Park.

Police said the cause of the accident was being investigated and the driver would undergo blood tests to check if he was driving illegally.

Thailand has one of the world's worst road safety records. Ministers have set the goal of reducing fatalities from 32.7 deaths per 100,000 people to 12 per 100,000 people by the year 2027.

However, a lack of road safety education in schools along with notoriously easy driving tests, police failures to enforce road laws, and chronic under-investment in infrastructure, all appear to hamper the efforts.