Two people were injured when five vehicles were caught in a horror pile-up crash in Thailand.

The cars were driving along Highway 304 in the Kabin Buri district of Prachinburi province when an ambulance ran a red light at the intersection on November 3.

Other drivers braked to let it pass, but they were struck by a speeding truck that kept barreling forward.

Footage shows how the large vehicle smashed into a pickup truck, crumpling it before flipping over sideways on the road.

Rescuers arrived and pulled out two wounded people stuck in the wreckage. They had to use metal cutters to free the injured from two trucks, who were then stretchered onto an ambulance and taken to a hospital.

Piles of wheat had also spilled onto the road during the accident.

Chaiyaporn Klaiubon, 34, driver of the grain-carrying 18-wheeler, said: 'I was on my way to the Thai food factory.

'When the light turned green and the vehicle beside me pulled away, I tried to move to the left lane. However, the car in front of me had braked, so I swerved around it, resulting in the mishap.'

Samorn Tontapha, whose dashcam captured the horrifying crash, said: 'I had come from Bang Nam Priao and was on my way to Kabin Buri to deliver goods.

'When I reached the stoplight, an ambulance from the other side ran a red light. I instantly braked, but the vehicle in front was unfortunate to be hit full force by a truck.'

The pile-up had caused a traffic build-up of more than five kilometres as officials cleared the road.

Authorities said they will examine the CCTV footage and interrogate the concerned parties to determine the cause of the accident.