Volunteers in charge of delivering necessities for residents under home quarantine pose for a group photo at a residential area at Liwan district of Guangzhou, capital of South China's Guangdong province, June 1, 2021. [Photo/Xinhua]

Guangzhou, Guangdong province, reported four locally transmitted COVID-19 cases on Sunday, including three confirmed cases and one asymptomatic carrier, as the city continues its prevention and control measures.

All the cases were detected in the medium- and high-risk areas in Guangzhou's Liwan district during mass screening in the area, as well as among close contacts with previous patients and asymptomatic carriers, said Chen Bin, deputy director of the Guangzhou health commission, at a news conference on Monday.

Because of the progress achieved in fighting the coronavirus, Nansha district resumed operations of its buses, subways, ferries, taxis, online car-hailing and other public transportation tools on Monday.

The district suspended all public transportation service late on Saturday when six members of a local family were confirmed with coronavirus, including asymptomatic carriers.

In Liwan district, a previously medium-risk housing estate on Longjin street was lowered to a low-risk designation over the weekend.

Despite the achievement, concrete measures continue to be introduced to prevent the spread of the coronavirus in the southern metropolis, which has a population of about 19 million.

According to Chen of the health commission, people who want to leave Guangzhou will be required to show negative coronavirus test results starting at noon on Monday to prevent the virus from spreading to other parts of the country.

Guangzhou has established 2,254 sample collection centers for nucleic acid tests, employing 34,657 medical workers. As of the end of Sunday, about 18.7 million samples have been collected, with six positive results reported in the past three days, Chen said.

Zhang Zhoubin, deputy director of the Guangzhou Center for Disease Prevention and Control, said local residents who have received a first dose of vaccine can make a reservation online for a second dose starting on Sunday afternoon.

The city temporarily suspended personal reservations for vaccinations starting May 31, as most of the city's medical staff have been sent to conduct mass testing to screen suspected COVID-19 cases.

Gu Zhongpeng, deputy director of the Guangzhou bureau of education, said the city's national college entrance examination, or gaokao, was safe and orderly on its first day. A total of 52,888 students participated in the examinations in the city this year. Of those, two asymptomatic carriers were able to take the examination in isolated wards at Guangzhou Eighth People's Hospital.

Guangdong reported five locally transmitted confirmed cases on Sunday. In Shenzhen, a man surnamed Luo, who had tested negative 11 times earlier, was found positive after his 12th test on Saturday. Luo, 45, a worker in the city's Yantian port, was confirmed with COVID-19 by medical experts after his test came out positive again on Sunday. Luo, whose case has been identified as an import-related one, has now been sent to Shenzhen Third People's Hospital for treatment.

The province detected another two asymptomatic carriers in Guangzhou and Zhanjiang on Sunday.