Authorities in south China's Guangxi Zhuang autonomous region are on the hunt for a cold-blooded menace currently at large on the Liujiang River.
However, the target of their manhunt is not a serial killer, but a group of piranha that recently attacked two people in the river.
Fishery authorities in the city of Liuzhou are offering 1,000 yuan (157 U.S. dollars) to local residents for every confirmed piranha kill. Two swimmers were attacked by at least three piranha in the Liujiang River over the weekend.
One of the victims had parts of his finger bitten off by the fish.
Experts and fishery officials said the piranha may have been brought to the country from the Amazon region in South America. Guangxi's tropical climate makes it similar to the piranha's natural habitat.
"Piranha can reproduce very fast in environments similar to home. In addition, the piranha have no natural enemies here to keep their numbers in check," said Zhou Jie, an expert at the Fisheries Research Institute of Guangxi.
Liuzhou fishery authorities have invited experienced fishermen to hunt the fish, said Wei Yongwen, head of the city's fishery and animal husbandry bureau.