Shanghai's COVID-19 epidemic control office announced on Tuesday that the municipality has begun to strengthen health screening for travelers or residents returning from a middle-risk area for epidemic prevention and control.

The measures, which took effect on Tuesday, came after a domestic region reported confirmed COVID-19 cases in the previous days. A middle-risk area refers to a district where no more than 10 cases are confirmed or a cluster of five or more patients are found within 14 consecutive days, according to the country's regulations.

The measures stipulate that communities screen all individuals coming from Qingdao within the past 14 days. These individuals must also undergo a 14-day quarantine at home, starting from the day of their arrival in Shanghai.

All those who arrived in the municipality from the area from Sept 30 to Oct 6 will have to take a free nucleic acid test. Those who arrived from Oct 7 to Oct 12 have to take two free tests.

All individuals who arrived in Shanghai from that region as of the beginning of Tuesday should report to their residential neighborhood communities and employers or the hotels that they reside in within 12 hours of arrival. They are subjected to 14 days of home quarantine and will go through nucleic acid tests for twice, according to the measures.

Schools have also been required to strengthen checks on students' health codes. All students, teachers and other employees who returned from the region would be subjected to a 14-day home quarantine and two nucleic acid tests.

The municipality's medical institutions at all levels need to conduct epidemiological screening for all the individuals seeking medical advice, and those who came from or returned from the region must take the nucleic acid test.

The Loushanhou community in Qingdao city, Shandong province, was announced as a middle-risk area for virus infection on Monday evening.