The men were apparently attacked by a piranha as they bathed a dog in the Liujiang river in Liuzhou city, Guangxi province.
Officials offered a reward of 1000 yuan (about £101) to anyone who captured a piranha – dead or alive – from the river.
According to local media, people rushed out and caught bundles of fish after hearing of the reward – but no one has hooked a piranha as of yet.
One of the bitten men caught the fish to show officials and claimed he had spotted two more of the flesh-eating fish in the river.
It is believed that the fish – native to South America – were illegally imported. They may have been released by people who bought them for aquariums.
Experts have commented that piranhas are unlikely to survive the water temperatures in the area for long and expressed concern that overfishing as a result of the reward offer could damage the river’s ecosystem.
Image: Jennifer Carr