NANJING, Dec. 19 (Xinhua) -- Customs authorities in the city of Nantong, east China's Jiangsu Province, caught five people in a suspected sugar-smuggling case earlier this month, local authorities said Thursday.

Customs officers seized a ship carrying around 600 tonnes of Thai sugar in the waters of Nantong section of the Yangtze River on Dec. 11. Preliminary investigation showed the sugar had no import certificates.

The case is under further investigation.