Experienced nurses are stationed at airports to help customs officers take samples.

Shanghai ordered people arriving in the city from other countries to undergo nucleic acid testing (NAT) to screen for coronavirus from Monday, the city's health commission announced on Sunday.

Wu Jinglei, director of the commission, said they have dispatched teams of experienced nurses to local ports to help customs officers take samples.

The new measure will expand a program that previously only applied to those coming from 24 heavily-hit countries, no matter their nationality.

Wu said all districts will give nucleic acid tests to new arrivals at temporary checkpoints to strengthen the screening.

Seventeen close contacts with a coronavirus patient that was confirmed in Jinan, Shandong Province on Saturday have been traced by the Shanghai Center for Disease Control and Prevention, according to Wu. They are still looking for the others who may have had close contact with the person from overseas who once stayed in Shanghai for a while.

Last week, the Shanghai government ordered people arriving in the city from 24 heavily-hit countries where they lived or traveled within the past 14 days to undergo 14-day quarantine at home or designated places.