The city of Dalian in Northeast China's Liaoning province collected samples from some 3.44 million residents for coronavirus testing by Thursday noon, according to the city health commission.
Dalian launched citywide nucleic acid testing on Tuesday in the wake of new COVID-19 cases reported recently. The tests, which will cover all city residents, are likely to last for three days.
The daily testing capacity of the city reached 2 million samples with the help of medical teams summoned from outside Dalian, the commission said.
Though Thursday noon, results of tested samples from the regions except the Jinpu New Area were negative. More samples will be tested and released.
The city's latest round of infections began on Dec 15 when four port workers handling cold-chain food products were found to be asymptomatic carriers in Jinpu New Area, making it the key region in the city.
Dalian has reported 12 confirmed, domestically transmitted COVID-19 cases and 20 asymptomatic, domestically transmitted cases, as of Wednesday.
There is a good supply of materials for epidemic prevention and control, as well as for residents' daily necessities in Dalian, Cong Ke, director of the city's Commerce Bureau, said at a news conference on Thursday.
For example, Dalian's daily production capacity of masks is 20 million. It also can produce 150,000 pairs of gloves and 30,000 protective face masks every day, Cong said.
Also Liaoning's capital city, Shenyang, reported one new asymptomatic case on Wednesday from 3 pm to the end of the day. That new case is the husband of the confirmed case of a 67-year-old woman surnamed Yin returning from South Korea, according to Shenyang's health commission.
A total of 1,133 people related to the confirmed case have been tested, the commission said.
Two residential compounds, where the confirmed case and her close contacts live, were classified as COVID-19 medium-risk zones. And 7,580 residents took nucleic acid testing and all results came back negative.
Three of the five medical institutions, where Yin had been to, are suspended for business. All five medical institutions have been disinfected.
Two schools related to Yin's family suspended class, and 611 teachers and students took nucleic acid tests, all with negative results.