The spread of Beijing's latest infections of COVID-19 has been effectively contained, but there remains an unprecedented challenge for epidemic control given the perpetual risk of imported infections, said local health authorities Wednesday.

Between midnight to 3 pm on Wednesday, the capital reported 17 new locally transmitted COVID-19 cases, including 16 from quarantine locations and one from the community, according to the Beijing Center for Disease Prevention and Control.

Beijing is facing a complicated situation of epidemic control and prevention, according to an online news briefing held by the city government on Wednesday. However, the current situation has been largely contained despite sporadic cases at the community level.

On Tuesday, the city reported 19 locally transmitted cases, including 18 from quarantine locations and one from the community.

One of the cases reported Tuesday was a woman surnamed Li, who had traveled to Beijing's Chaoyang district on Monday by train from Fujian province. According to Chaoyang police, she had received an alarm on her Beijing Healthkit — a mobile-based app used to check health codes and provide nucleic acid testing results. The alarm warned her not to return to the capital due to infection risks from Fujian.

She failed to report the status on the app and went to many public places upon arrival in Beijing. Li has been placed under criminal investigation for obstruction of the prevention and control of infectious diseases.

Universal Beijing Resort announced on Wednesday that it will be temporarily closed due to epidemic control requirements.

Tongzhou district, where the resort is located, reported two new cases on Wednesday afternoon. The resort was included on the list of places the infected people had been to, according to the district.

It is the second time Universal has had to suspend its operations this year after a nearly two-month suspension from May 1 due to a resurgence of COVID-19 infections in Beijing.

The resort said it will continue to follow related control policies and assess their impact on operations, and make great efforts to reopen as soon as possible.

Full refunds and rescheduling will be offered to those affected, according to the resort.

Nationwide, a total of 297 locally transmitted confirmed COVID-19 cases were reported on the Chinese mainland on Tuesday, according to the National Health Commission. The provinces of Shanxi, Guangdong, and the Inner Mongolia autonomous region, are where the majority of the cases are located.

In the southern metropolis of Guangzhou, which has a population of over 18 million, local COVID-19 infections continued to rise, with 27 new confirmed cases and 46 asymptomatic carriers reported in the city on Tuesday, according to the local health commission.

"The risk of continued infection in this round of the COVID-19 pandemic is still high, as infected people have had a wide range of social activities in urban villages, restaurants, factories, entertainment venues and other densely populated places," said Zhang Yi, deputy director of the Guangzhou Health Commission, at a Wednesday news conference.

In the city's Haizhu district, the area with the most cases, most infections are associated with a transmission chain from a restaurant in Guitian, an urban village in Haizhu, according to Zhang.

Dine-in service has been suspended or restricted in the districts of Huadu, Baiyun, Haizhu, Yuexiu and Panyu.

In Nanjing, Jiangsu province, its population of around 9 million has been urged to take nucleic acid tests after the city reported 13 locally transmitted asymptomatic carriers and one confirmed case of COVID-19 on Tuesday.

All those infected were workers at a railway freight center and their close contacts, according to the provincial health commission on Wednesday.

The city has asked all travelers arriving in Nanjing from outside Jiangsu to take three nucleic acid tests in three days and report to their hotels, communities or workplaces.

Ye Zizhen and Yao Yuxin contributed to this story.