Thailand is tightening restrictions on dairy products from China after finding two samples of milk powder contaminated with melamine, Deputy Health Minister Wicharn Meechainant said Tuesday. "We'will issue a new ministerial regulation very soon that milk imported from China must be checked more thoroughly," he said. Sixty tons of milk powder imported from China were impounded Monday after Thai Food and Drug Administration inspectors found traces of melamine, Wicharn said without disclosing the level of melamine concentration. Also Tuesday, the Anglo-Dutch company Unilever said it was recalling some of its Lipton-brand milk tea powder in Hong Kong and Macao after traces of an industrial chemical were found. Unilever did not say whether the tainted products were manufactured in mainland China, but they are distributed in Hong Kong and Macao.