BEIJING - Chinese quarantine inspectors stopped 137 shipments of substandard imported food in May, the country's top quality supervisor said on Thursday.

Microorganism contamination and banned food additives were the major problems with the shipments, which came from 26 countries and regions, Chen Xitong, spokesman of the General Administration of Quality Supervision, Inspection and Quarantine, said at a press conference.

Chen said the products were either returned to sender or destroyed and did not enter the Chinese market.