Four Por Teck Tung Foundation workers were wounded in the latest scuffle between private rescue agencies over territorial rights in Bang Bon district on Wednesday night.
The brawl took place less than a week after rescuers from Siam Ruam Jai and Ruam Katanyu foundations clashed in Bang Kapi district. The incident left two people injured and five vehicles damaged.
Police who were called to the PTT petrol station on Ekkachai road about 11.30pm found pools of blood and many cars peppered with bullet holes.
The four injured workers had already been taken to Bangkok Inter 8 hospital.
Police said Prapan Loomjan, 33, was shot in an eye socket and was later transferred to Kasemrat hospital in Bang Kae district.
Apirak Rakjang was wounded in the stomach and later transferred to Luang Phor Taweesak hospital.
A bullet grazed the neck of Anek sae To, 39, and his left leg was broken by another bullet.
Another rescuer, Jeerask Fuangsantae, received a cut on the arm.
Eyewitness and Por Teck Tung rescuer Nattapong Suwanrat said the incident took place after his team received a report of a car crash outside the petrol station.
When they arrived, they found Mr Prapan wounded in the back of a pick-up truck. Three other trucks were riddled with bullets, he said.
"I saw Siam Ruam Jai rescuers shooting at our foundation staff with their boss urging them to 'get rid of them all', before fleeing the scene in two pick-up trucks and a van," Mr Nattapong said.
He said both foundations had previously agreed on the areas where each would aid victims of road accidents. But over the past couple of months, Siam Ruam Jai workers had strayed from their assigned territory.
Metropolitan Police Bureau spokesman Pol Maj-Gen Suporn Pansua said the violence might have stemmed from a personal conflict. But police would arrange for the heads of both foundations to meet and discuss how to prevent further conflict.
He said those involved will be arrested. Police in the district have been told to check the rescue workers for weapons.
Surachet Sathitniramai, acting secretary-general of the National Institute of Emergency Medical Services System (Narenthorn Centre) under the Public Health Ministry, said talks will be held with the Disaster Mitigation and Prevention Department and representatives from private rescue units on how to curb violence between rescue workers.
Dr Surachet said brawls between rescue teams stem mainly from conflicts over under-the-table fees paid by some private hospitals to rescue units that bring them patients.
He said the law does not punish private hospitals from paying the fees, so the ministry could only ask them to stop the practice.
Sometimes, brawls break out only because the workers are young and hot-tempered, he said.
The Medical Emergency Act, which took effect in March, does not cover disputes between rescue units as it focuses mostly on the promotion of medical emergency services by non-state agencies and protects patients from substandard rescue operations.
The institute is not authorised to supervise or control the operations of private rescue units, Dr Surachet said.