With Shanghai's COVID-19 situation easing, local authorities have given the green light for the reopening of four metro lines and 273 bus routes from Sunday.

One of the resumed metro lines is Line 3, which goes to the Shanghai Railway Station and the Shanghai South Railway Station.

Despite the reopening, it seems it will take some time for passenger numbers to return to normal. Around a dozen passengers got off each train at the metro station linked to the Shanghai Railway Station on the first day.

"We are not seeing many passengers today. The figure is definitely fewer than usual," said Zhu Lin, deputy manager of the metro station.

Trains come every 20 minutes — a much lower frequency than before. Most passengers were carrying luggage and heading to the railway station.

Strict prevention and control measures are also in place.

Passengers must show a negative nucleic acid test result from within 48 hours and scan the QR code at the station to make a record. 

The same requirements are also being enforced for passengers taking buses.

The public transport lines that have resumed operations so far are intended to help people move around the city with greater ease. They service railway stations, airports and hospitals. 

City officials also said more metro and bus lines will open depending on the future development of the COVID-19 situation in Shanghai.

The Chinese mainland on Saturday reported 157 locally transmitted confirmed COVID-19 cases, of which Shanghai and Beijing both reported 52, the National Health Commission said on Sunday.

Apart from Shanghai and Beijing, five other provincial-level regions on the mainland also saw new local COVID-19 cases.

Shanghai also reported 570 locally transmitted asymptomatic infections of the novel coronavirus Saturday, out of a total of 667 local asymptomatic carriers newly identified on the mainland.