China has rejected another five shipments of corn from the United States that contained unapproved genetically modified ingredients, the country's quality watchdog announced on Wednesday.

Entry and exit quarantine authorities in Fujian and Shandong provinces, as well as in Shenzhen, Guandong province, rejected five shipments of corn from the US that totaled more than 12 metric tons after they were found to contain MIR 162, a genetically modified ingredient that has not been approved for import by agricultural authorities, the General Administration of Quality Supervision, Inspection and Quarantine said in an online news statement.

In November, Shenzhen also rejected a shipment of corn from the US.

According to a regulation on genetically modified products issued by the State Council in 2001, only GM products that have been on the market and proven to be free of hazard to humans and the environment can be imported to China.