A giant snail species from Africa that poses a threat to human health and agriculture has been found in Fuzhou, the capital of Fujian province, xinhuanet.com reported on Thursday.

It is not clear how the snails arrived in the city, although local ecologists say they might have reached China accidentally through an imported shipment in the 1930s.

The snails, which are as big as a child's fist, eat about 500 plant varieties, including peanuts and melons. They also contain parasites that transmit tuberculosis and a form of meningitis.

Ecologists say the snails might have been bred by locals for sale to restaurants. They urged the authorities and the public to be wary of the snails.