The Chinese city of Qingdao said on Monday that it will test its 9 million, or 90 lakh, citizens for the coronavirus after a dozen cases were found in a hospital, BBC reported.

In a statement, the Qingdao municipal health commission said that six new and six asymptomatic cases were discovered from a hospital that was treating Covid-19 patients coming from abroad.

The commission said that five districts will be tested within three days and the whole city would be done within five days, according to AFP. It said that about 1,14,862 people, including medical staff and newly-hospitalised patients, have already undergone a test and been found negative for the infection.

The cases in the city were reported following China’s Golden Week holiday in which millions travelled across the country. The port city had a footfall of 4.47 million or 44.7 lakh arrivals during this holiday period, according to a Global Times report.

Qingdao authorities have also called people from the nearby city of Jinan for the test if they visited after September 23.

China has so far officially reported 90,812 Covid-19 cases, with the toll at at 4,739. The country has claimed to have largely controlled the infection. However, last month, Qingdao had reported that two port workers handling imported seafood were found to be positive.

On August 15, four cases were found in the city of Urumqi in the Xinjiang region, according to AP.

The country had earlier conducted mass testing on 11 million (1.1 crore) people in 10 days in Wuhan. To carry out the tests, many centres were opened involving thousands of staff. The country had sped up testing by using batch- or pool-testing. In this method, a test is conducted on a batch of five to 10 samples. If any came back positive, the health officials would conduct individual tests so find out who was infected.