Authorities in Shanghai were seen putting up barriers following protests against COVID-19 measures. Meanwhile, a British minister condemned the arrest of a BBC journalist who was covering the demonstrations.
Shanghai authorities ramped up security in the city on Monday after hundreds of people protested against COVID-19 measures.
There was no sign of fresh protests on Monday in Shanghai as barriers were placed around the city center.
On Sunday, protesters chanted slogans against President Xi Jinping and the ruling Chinese Communist Party (CCP).
Demonstrations spread to various cities outside of China on Monday, as people showed solidarity with the protesters. Small-scale vigils and protests, organized by Chinese expats and overseas students, were seen in cities including London, Paris, Tokyo and Sydney.
Chinese police have detained three people at a site where demonstrations had been held over the weekend, the Agence France-Press (AFP) news agency reported.
A police officer told AFP that one of those detained "didn't obey our arrangements."
Police were also ordering people to delete photos from their phones, AFP said.
Posts circulating on Chinese media platforms have claimed that COVID-19 lockdowns hampered rescue efforts after a blaze broke out in Urumqi, the capital of the northwestern Xinjiang region.
The fire killed at least 10 people in apartment building in the city, where some people have been locked in their homes for four months.
At a press briefing, Foreign Ministry spokesperson Zhao Lijian said: "On social media there are forces with ulterior motives that relate this fire with the local response to Covid-19."