A speedboat crashed into a ferry injuring four tourists on a river in Bangkok, Thailand, on Thursday afternoon.

The wooden longtail motorboat was taking the holidaymakers for a sight-seeing tour along the Chao Phraya River when it lost control on June 6 at 5 pm local time.

Pictures show how the vessels collided, with the bow of the motorboat piercing through the roof of the ferry. Four Chinese tourists - three men and a woman - were injured. They were carried to the Tha Phra Chan pier before being rushed to the city's Hua Chiew Hospital. 

Police named the victims as Zhou Jiajia, Huang Donglan, Luo Jinhui, and Zhao Wei. They were all later discharged with minor injuries.

The day trip tour boat sustained damage and sank near the scene while the ferry was taken ashore to be repaired.

According to witnesses, the incident occurred during rush hour after work, with several boats navigating the choppy water and heavy winds in the same area. The conditions are said to have caused the tour boat to lose control.

Onlooker Auan said that the boats then collided as they were unable to steer away from each other.

He said: 'I think the captain or steersman might not have been careless but it looked like they crashed due to something blocking their vision or the current changing direction.'

Another witness, Jeerasak Kamollak, added: 'I am a staff member from the electric boat at Wat Arun. 

'I was drinking a bottle of water when I heard a long horn sound and looked up, then I saw two boats colliding against each other, causing a loud noise in the river'

Police said they planned to question witnesses and gather evidence from those involved to investigate the cause of the accident.