China's top quality watchdog said Friday that it has ordered a ban on the imports of some food and agricultural produce from Japan amid concerns of radiation contamination.

China has banned imports of dairy products, vegetables, fruits, aquatic animals and other related products from five prefectures including Fukushima and Tochigi, the General Administration of Quality Supervision, Inspection and Quarantine said in a statement on its website.

The nuclear crisis in Fukushima triggered by a devastating earthquake has seriously contaminated local food and agricultural produce, the statement said.

The ban took effect on Thursday, the statement said, but did not say how long the order would remain in effect.

It has also asked local quality monitoring authorities in China to strengthen inspections of radiation levels on other food and agricultural produce imported from the five prefectures to prevent contaminated food from entering China.

Food and agricultural produce from other regions of Japan should undergo testing and risk analysis for radiation to ensure food safety, it added.