The domestic COVID-19 epidemic is trending downward overall, but sporadic cases are still appearing in Beijing and Shanghai as the three-day Dragon Boat Festival holiday starts on Friday, according to authorities.

Lei Zhenglong, deputy director of the National Health Commission's Bureau of Disease Prevention and Control, said during a news conference on Thursday that the number of locally transmitted infections nationwide had dropped to below 100 for three consecutive days.

The mainland registered 18 locally transmitted confirmed cases and 43 asymptomatic cases on Wednesday, according to the commission.

Lei said that Shanghai, the economic powerhouse battling a protracted fight against the virus, is easing epidemic control restrictions.

"But sporadic infections in communities are still emerging, and precautions that have been in place should be maintained to prevent a resurgence," he added.

According to health authorities in Shanghai, the city registered 13 local cases on Wednesday and seven by about 5:30 pm on Thursday.

The city will make routine nucleic acid tests more accessible to residents by adding more testing stations and prolonging service hours.

Lei said that as the Dragon Boat Festival begins, local authorities have been urged not to implement additional movement restrictions on travelers, including those from Shanghai.

In Beijing, the number of new cases is declining, but fresh infection clusters that recently surfaced in Jilin and Liaoning provinces in Northeast China are developing, according to Lei.

Xu Hejian, spokesman of the Beijing municipal government, said 13 of its 17 districts had reported no new cases at the community level for seven straight days. Normal public transportation and business reopenings are resuming in these areas.

The nation's capital reported 14 local cases on Wednesday and five by 3 pm on Thursday.

The Beijing Education Examinations Authority announced on Thursday the delay of two major exams that were scheduled to be taken later this month by students in their second year of junior high school.

On Thursday, the State Council's Joint Prevention and Control Mechanism also released a circular aimed at ramping up oversight of nucleic acid tests. The move comes after several testing companies were found to be committing fraud by diluting or intentionally dumping samples for illegal gains.

The document said institutions that provide fake results or hire untrained health professionals to perform tests will be shut down, and public security authorities will deal with individuals suspected of violating laws.

It added that testing facilities that receive a large number of complaints or fail third-party assessments will be given warnings and ordered to rectify the problems immediately.

"The results of the inspections conducted on testing companies should be released to the public in a timely manner to create effective deterrence," the circular said.