Linyi, Shandong province, has seen a decline in new COVID-19 cases, with all newly reported infections being from quarantined groups, after the city implemented strong virus containment measures.

The city registered two confirmed cases and 54 asymptomatic ones on Monday. It reported 26 confirmed and 262 asymptomatic cases as of Sunday, according to the provincial Health Commission.

Linyi reported the first infection in Lanshan district on Wednesday. Most of the infected people were reported in Lanling county, with about 60 percent of them students.

The city, with a population of 11 million, started tracing infected people and their contacts immediately after the first infection was reported. All were from quarantined people, and transmission chains within the COVID-19 cluster could be traced, local officials said at a news conference on Tuesday.

The spread of COVID-19 in the city has been minimized and has not spread to other cities, they said.

The final exam season and teachers' monitoring exams contributed to the spread of the virus in the city recently. All infected students, teachers, close contacts and sub-close contacts have been quarantined, they said.