TAIYUAN, Nov. 25 (Xinhua) -- The city of Huozhou in north China's Shanxi Province has found that an imported frozen food packaging sample tested positive for the novel coronavirus, local health authorities said on Wednesday.

According to the epidemic prevention and control team of Linfen, which administers Huozhou, the sample was taken from frozen freshwater shrimps imported from Ecuador.

Local authorities have sealed the products, quarantined, and conducted nucleic acid tests on relevant personnel who had direct contact with the food. So far, all results showed negative.

China has increased efforts to block COVID-19 through imported foods, with the Ministry of Transport releasing a guideline in mid-November to prevent the transmission of COVID-19 through imported cold-chain foods in road and water transportation.

The State Council joint prevention and control mechanism against COVID-19 has also unveiled a plan to realize full-chain, closed-loop, traceable management of imported cold-chain foods. They vowed to conduct complete disinfection of those products, novel coronavirus tests at the ports, and ensure all imported cold-chain foods entering the market are traceable.