18 people were killed when a bus crashed in Bangkok, Thailand on Wednesday, police said.

The bus that crashed was one of three double-decker buses accompanying local government officials on a field trip to the ancient Buri province, east of the capital Bangkok.

'In the accident, 17 people died on the spot and one person died during treatment at the hospital,' Police Lieutenant Colonel Sivapas Furipchaibunchu said. He said, 'When we questioned the driver, he said that the bus fell off the road due to brake failure. Further investigation is underway .'

When the bus accident happened, there were 49 people on the bus and the injured were taken to two hospitals for treatment.

According to the World Health Organization, Thailand has the worst road safety record. About 20,000 people die here every year due to road accidents.

Old and unsafe vehicles and carelessness of drivers are considered to be major factors in road accidents .