Three people are dead after a train crashed into a double-decker bus carrying holidaymakers in Thailand.

Video footage of the accident in Nakhon Chaisri district shows the bus slowly crossing the railway when a train ploughs into it at full speed, whipping the vehicle around.

The bus driver was killed instantly and two passengers later died in hospital.

At least 30 people were injured.

The bus was taking a group of workers from a nearby factory in Nakhon Pathom province west of Bangkok to the southern island of Koh Samui for a holiday trip, according to local police officer Thanachot Shinwongsa.

There appeared to be no lights or other warning devices at the intersection, a common failing at many unregulated railway-road junctions in Thailand.

Other cars were seen driving over the tracks alongside the bus just seconds before the collision.

Thailand has the world's second most dangerous roads in terms of per capita deaths.

The World Health Organization estimates about 24,000 people die each year in road traffic accidents.

In January three people were killed and scores injured when a truck crashed into the side of a passenger train several hours south of Bangkok.