CHENGDU, Dec. 9 (Xinhua) -- Chengdu, capital city of southwest China's Sichuan Province, reported zero increase in new domestically transmitted COVID-19 cases and asymptomatic cases from 9 p.m. Tuesday to 6 p.m. Wednesday, while citywide nucleic acid tests are continuing, local authorities said.

Xie Qiang, director of the municipal health commission, said at a press conference that by 8 p.m. Wednesday, 433 close contacts of previously confirmed cases and asymptomatic cases had been traced. Of these, swab samples had been collected from 344 people, with 338 results showing negative for COVID-19, while the rest of the results are yet to be released.

By 9 p.m., the city had dispatched 2,458 sampling personnel from 33 testing agencies to carry out nucleic acid tests in key areas where the cases were reported. The city has sampled 739,000 people, with 483,800 of them sampled on Wednesday. Nucleic acid tests were conducted on 399,300 people and all tested negative for COVID-19, Xie said.

Since the cluster of local transmission was first reported on Monday, a total of 630 environmental samples have been collected in the city, of which 14 were positive for COVID-19 and 553 were negative. The rest of the results are yet to be released. A total of 140 food samples were tested, and the results were all negative, Xie said.