Adisap Piriyakul, a 23-year-old Por Tek Tung Foundation member, died after being shot in the chest, while the two injured included Jeddanai Issaradeth and another unidentified man, according to police.
The victims were rushed to Kasemrad Sukhaphiban 3 Hospital in Saphan Sung.
The incident occurred after crews from Rom Sai Foundation, another ambulance network, accused crews from the Por Tek Tung Foundation of encroaching on “their territory” when responding to a traffic accident.
Police said a large number of Rom Sai members allegedly attacked Por Tek Tung members with handguns at 1am on Sunday night.
Nipol Thongpradit, a Por Tek Tung crew-member, said: “We explained to them [Rom Sai Foundation crew] that we are just volunteers helping society and there was no need for us to be against each other.”