People in East China’s Fujian Province’s Putian are discouraged from leaving the city from Sunday as 24 COVID-19 infections were reported.

All reported 24 positive COVID-19 cases – six confirmed and 18 asymptomatic cases – are from Putian’s Xianyou county, the biggest county of the city. Villages in Xianyou where confirmed cases live were sealed off.

In principle those in Putian should not leave the city and those who must leave must hold a negative nucleic acid certificate taken within 48 hours, the city’s anti-epidemic group said in a notice released on Sunday.

Public venues such as cinemas, museums and libraries must suspend their indoor activities. Restaurants should limit their operation hours, it said. People are encouraged to work from home.

The city’s anti-epidemic group also stressed daily preventive measures including wearing masks and having body temperature and QR health code checked when people enter public venues or take public transportations.

Moreover, education authorities in Putian are requiring schools in medium- and high-risk regions to suspend classes, but other schools are operating normally.

Students must wear masks in class and the authorities are asking students to get fully vaccinated. The vaccination on teachers and students aged between12 and 17 is expected to be finished before Wednesday.

Buses, scenic spots, libraries and amusement venues in Xianyou suspended operation from Saturday. The Xianyou train station has stopped receiving new passengers.

The first two detected cases were students from a family in Xianyou but experts suspect that the outbreak may be caused by a patient who recently returned to Putian from Singapore.

The patient surnamed Lin, a father of a student, came back from Singapore on August 4. Lin had undergone 14-day quarantine in Xiamen and a seven-day home health monitoring during which Lin took nine nucleic acid and serologic tests, but they were all negative. He tested positive on Friday.

Primary studies on the virus suggest it is the Delta variant, local authorities said at a Saturday press conference.