All four were taken to Thalang Hospital for treatment and are expected to recover fully.
According to Thalang police, the group had just finished catching fish in a lake behind a palm-tree plantation near Wat Ta Rua temple and were sitting, divvying up the catch when someone opened fire with a shotgun.
Kittisak Pongpan, 32, was hit by four pellets – two in the right arm, one above his right eyebrow, and one in the back. Dechanan Pongpan, 38, got a pellet in the right arm.
Mr Somjai Tee-uthit, 49, was hit by six pellets, four in the right leg and two in the left leg, while Saijai Bunrat, 50, was hit twice in her right leg.
The investigation is on-going, though police say there are two likely scenarios: someone was offended that people were fishing in the lake, or the shooter had a dispute with one of the victims.