Image caption Piranhas are known to be ferocious

A city in China is offering cash rewards to anybody who captures flesh-eating piranha fish from a local river, after reports that two men were bitten.

Liuzhou city in southern Guangxi province has offered 1,000 yuan ($157; £101) to those who retrieve one - dead or alive - from the Liujiang river.

Local media say people rushed out after the announcement and caught many fish - but no piranhas so far.

Officials believe they were released by people who bought them for aquariums.

Piranhas, native to South American rivers, are believed to have been illegally imported to China.

Two local men were reportedly attacked by a piranha on 7 July when one of the men bathed his dog in the river.

The man caught the fish for identification, and said he saw two others in the river at the same time.

Lines of people with rods and nets were seen on the river banks in Liuzhou. The government has even provided free meat to use as bait.

But experts believe the fish would not be able to survive for long in any case as water temperature in the area drops below 15C in winter.

They also warned that local government might be doing more harm than good as the frantic fishing campaign could end up damaging the river's ecosystem.