Dozens of spectators were injured when a bridge collapsed at a drag boat racing evening inThailand.

The 3ft wide concrete bridge runs along the Bong Ngu Hao canal in Samut Prakan, province but was not able to carry the weight of hundreds of visitors cheering on the competition on August 24.

The upper part of the bridge, which was more than 30ft high from the water surface, was the most popular spot because it has the best view to watch the racing boats.

When the races started, people were cheering while jumping on the bridge with excitement.

However, the event was interrupted when the bridge suddenly collapsed into the water with more than 50 people on it.

All of them fell down into the canal and eight people were seriously injured after they hit the thick cement thick below. Another five canoes moored near the bridge were also hit,

A spectator witnessed the accident said: "It happened so quickly. All of us were shocked when we heard the screams from the upper part of the bridge."

Rescuers dived to find boats that were sunk by the thick concrete while some visitors were still stuck on the cracked poles waiting for help.

All the injured people were assisted at the scene before being taken to the hospital.

Police Colonel Worawut Pankhow, the commander from Bang Sao Thong police station arrived at the scene with District Officer Atthaphon Samsen to investigate the accident.

He said: "The organisers of the speedboat racing event will be questioned to find whether they had the correct permission to hold the gathering.''