BEIJING — The joint prevention and control mechanism of China's State Council has released a circular ordering increased epidemic prevention and control for port cities in a bid to further prevent imported infections.

People traveling from land port cities other than those connected to ports in Hong Kong and Macao should present a negative result of a nucleic acid test taken within 48 hours of departure, the circular said. Those traveling to land port cities should take at least one nucleic acid test upon arrival.

These requirements should be enforced from the date relevant localities confirm and announce the specific areas covered by local epidemic prevention and control measures until March 15, 2022, the circular said.

It also said that eligible port cities can consider establishing buffer zones for epidemic prevention and control within their jurisdictions.