China has imposed a strict lockdown on nearly half a million people in a province near the capital after a small surge in cases.
Authorities have warned that the outbreak in Hebei province's Anxin county was still "severe and complicated".
Anxin would be "fully enclosed and controlled", with restrictions similar to those imposed in Wuhan, where the outbreak first emerged.
The move comes after Beijing recorded 14 new cases in the last 24 hours, bringing the total number of cases linked to the Zinfai wholesale food market to 311.
According to state news agency Xinhua, businesses in Anxin had supplied freshwater fish to the Xinfadi market.


US and Iran signal a peace deal is close
Qatar rejects media report on energy production decisions
Trump says Iran war deal close as Strait of Hormuz tensions linger
Victims' families mark Air India crash anniversary with prayers and tributes
Ebola outbreak spreads to crowded displacement camp in Congo
Fire breaks out at New Zealand's Wellington airport, disrupting flights
Ukraine and Russia trade overnight drone strikes, officials say
UN says Taliban arrest 30 women for violating hijab rules in Afghanistan
