Footage shows firemen dousing the wreckage of a school bus that burst into flames killing at least 13 pupils who were on a day trip in Thailand today.

The coach was carrying kids from the Wat Khao Phraya Sangkharam School in Uthai Thani province to an electricity plant for an education visit when it caught fire on a road in Pathum Thani province on the outskirts of Bangkok at around 12:38 pm local time.

Dramatic footage shows flames engulfing the entire vehicle as firefighters battled to put out the inferno.

Officials said at least 13 children were killed when they were burned alive as they scrambled to escape. They said they were in Grade 3, making them around nine years old.

Pictures from the scene showed their charred corpses in the burned-out vehicle. Firemen took some of the children who were able to escape the blaze into a nearby building, where they were seen being counted.

Politicians visited the scene of the wreckage to express their condolences.

Speaking on the roadside, one teacher said: ‘We are from Wat Khao Phraya Sangkharam School in Uthai Thani with three buses.

‘The incident occurred on the second bus.'

A driver of one of the school vehicles in the convoy told local media that he saw the front wheel of the bus explode before flames appeared.

A witness said they heard an explosion before seeing the bus travelling at high speed, followed by an accident with a burst of flames and smoke.

Another witness said that officers were hesitant to approach the scene while the bus was burning, prompting students to huddle together inside the vehicle.

The owner of the rented coaches from the Chinnaboot Tour company said that his buses picked up students at their school in Uthai Thani before travelling to the head office of the Electricity Generating Authority of Thailand for a school trip.