HONG KONG - MACAU authorities say three more children in the Chinese gambling enclave have developed kidney stones that may be linked to Chinese milk contaminated with the industrial chemical melamine.

A government statement says the three girls aged from 4 to 8 are in stable condition and do not require hospitalisation.

The Monday statement says the children attend schools where authorities provide students with free milk produced by Yili Industrial Group.

Yili is one of several Chinese dairies implicated in a scandal on the mainland in which melamine-laced dairy products have killed four infants and sickened more than 50,000.

Melamine is used to make plastics and fertiliser. -- AP