Beijing, China - Police officers were deployed in large numbers in several Chinese cities on Tuesday to prevent the resurgence of protests against the Chinese government's strict coronavirus containment measures that swept the country over the past few days.

A sweeping police contingent has been observed on the streets of the capital Beijing and other major cities such as Shanghai, Guangzhou, and Hangzhou since Monday.

Security forces increasingly stopped passersby and checked their phones for suspicious content or software, including VPNs that can be used to bypass online censorship.

In Beijing, law enforcement was particularly focused on securing the Liangma River promenade near the diplomatic quarter, where hundreds had demonstrated on Sunday evening.

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Meanwhile, in the financial hub Shanghai, barriers were set up along Wulumuqi Road to prevent large crowds from gathering, as they did on the weekend.

The recent protests, highly unusual in the Communist-ruled country with more than 1.4 billion inhabitants, were apparently triggered by anger about a deadly fire that broke out in a residential building in the regional capital of Xinjiang, Ürümqi, in which 10 people were killed over the weekend.

Several residents said on social media that the coronavirus restrictions had hampered rescue efforts. Large parts of the Xinjiang region and its capital have been under lockdown for more than 100 days.

"China's covid measures are scientifically based, correct, and effective," Foreign Ministry spokesman Zhao Lijian said on Tuesday in response to questions about the discontent that led to the protests.

China's health commission also responded to the unrest by saying on Tuesday that it plans to increase vaccination in nursing homes and that other measures already announced would be implemented "quickly and thoroughly" to reduce "inconvenience."

The commission did not say the prospect of a departure from the strict zero-Covid strategy was on the table.

China is currently seeing its highest Covid-19 case numbers since the beginning of the pandemic. On Tuesday, the health commission in Beijing reported some 38,400 new cases, a slight drop compared to the record of more than 40,000 set a day earlier.

Extensive restrictions on movement are currently in place in multiple Chinese cities with more than 1 million inhabitants, such as Beijing, the severely affected southern Chinese city of Guangzhou, and Chongqing.