Wikimedia Commons/Greg Hume

A Chinese city has cancelled a $159 bounty on piranhas after people killed too many other fish in a four-day hunt.

Authorities in the city of Liuzhou offered the reward to local residents last week for every confirmed piranha killed after a group of the fish attacked two people in the Liujiang River, state-run Xinhua News Agency reported.

Local residents were seen out on the river last week using pork, mutton and liver to bait the fish, Xinhua reported.

But on Friday, the local government called off the piranha hunt and withdrew the promise of a reward, the state-run China Daily newspaper reported.

No piranhas were caught during the four-day hunt, but too many other fish were killed.

The head of the local livestock and fishery bureau told the China Daily that many local breeds of fish were found dead in nets and he feared the ecological balance of the river was being damaged.

Piranhas are omnivorous freshwater fish that are native to South American rivers. They are known for their sharp teeth.