SHANGHAI, (Reuters) – A few COVID-19-related cases have prompted Shanghai to restrict tourism and a neighboring city to reduce public transport services. China has vowed to not tolerate clustering.

Three domestically-transmitted COVID-19 infections were detected in Shanghai. The cases had been confirmed as having occurred Nov. 25, according to data provided by the National Health Commission (NHC). In August, the last local manifestation of symptomatic disease in Shanghai was identified.

These new infections occurred just days after China had its largest outbreak of the Delta variant. This highlights the difficulty in eradicating local clusters.

China has stated earlier in the month that its goal is to contain and detect local infections as fast as possible.

Shanghai’s travel agency has been banned from organizing tourist trips that involve visits between Shanghai and other provincial-level areas.

A financial district of 24.9 millions residents has closed down a handful of residential properties deemed to be at higher risk of infection. Two local hospitals have also halted face-to–face services in order to comply with COVID controls.

Xuzhou, a city located in eastern Jiangsu, is approximately 9 hours from Shanghai. It reported a locally transmitted asymptomatic carrier on Nov. 25, who had been a close contact with a Shanghai-infected person. China separates asymptomatic cases.

This 9.1-million population city suspended its three subway lines. They also cut some long-distance buses and stopped some entrances to highways that connect it with the rest of the city.

The council advised residents to not leave the town due to unrelated reasons. Anyone who must travel must provide proof that they have received a negative result from a blood test within 48 hours.

Xuzhou requested that larger, face-to-face activities such as concerts and sports events be suspended. The order also asked schools to suspend offline classes from Friday to Sunday and required universities to improve their management of student requests to be removed.

The NHC data also showed that Hangzhou in eastern Zhejiang had two cases of local asymptomatic infections for Nov. 25.

As of November 25, China reported that there had been 98.583 cases in China with confirmed symptoms. These include both residents and foreigners. 4,636 people died in total.