Four boat drivers were injured in a brawl over passengers in Thailand.

Boat operators at the Bali Hai Pier in Pattaya were reportedly competing over tourists travelling to Koh Larn island, sparking the physical altercation on April 17.

Police later arrived to break up the fight. They said four people were injured including Wanchai Khanthawit, 51, and his son Watchai, 31, who were both stabbed.

Two other boat operators, Kecha Lumpa, 56, and his son Marut, 30, were bruised.

All of the injured were taken to the Pattaya City Hospital for treatment.

Locals said fights between workers at the Bali Hai Pier were frequent, as they often jockeyed for customers. They claimed authorities have so far been unsuccessful in curbing the violence.

A police spokesperson said: 'We have identified the suspected instigators and are gathering evidence from witnesses and security cameras to locate them for legal action.'