China's coronavirus outbreak intensified as growing cases in Beijing fueled fears of an unprecedented city lockdown, as officials raced to avert a Shanghai-style disaster that has already wreaked havoc on the financial hub.

Concerns about the country's strict adherence to COVID Zero sparked a panic buying spree as Beijing residents rushed to stock up on supplies, fearful of being caught unprepared in a citywide shutdown, after the government announced mass testing plans and placed some areas under lockdown.

After hundreds of infections were discovered over the weekend, the city of more than 20 million people and the country's political capital cordoned off dozens of residential compounds. They ordered residents of the eastern neighborhood of Chaoyang to be tested three times this week. Officials have warned of additional instances in the coming days, with Beijing city government spokesperson Xu Hejian stating late Friday that the current outbreak is "complex and stealthy," adding that the city government will take additional efforts to prevent its spread.

The outbreak comes as Shanghai reports a record number of fatalities and tightens regulations to eradicate illnesses. The simultaneous breakouts in two of China's most populous cities have created an unusual test for President Xi Jinping, who is expected to seek re-election to a third five-year term at the Communist Party meeting later this year.

China has frequently defended COVID Zero, claiming that the policy saves lives and keeps the economy afloat, even though the plan dims the country's growth prospects and risks disrupting global supply networks.

Beijing has already sealed off several residential compounds in the Chaoyang area, which is home to over 3.5 million people, many of whom are ex-pats, the core business sector and the majority of foreign embassies. It has designated 14 smaller villages as "sealed" zones and another 14 as "controlled" zones, each with varying movement restrictions.

On Monday, Wednesday, and Friday, local officials will conduct random drug testing of residents and workers in Chaoyang. This includes everyone from white-collar workers to tiny toddlers who require a negative result to enroll in kindergarten.

As residents wait for exams, long queues are already snaking around housing buildings. Fresh food, kitchen staples, and other essentials such as masks and antiseptics have all sold out online and brick-and-mortar grocery stores.

Residents in the capital are fearful of a replay of the crisis that engulfed Shanghai for over a month. Residents were unable to acquire food or medical treatment consistently. Beijing authorities have bolstered supplies, providing fresh veggies to areas of Chaoyang where positive cases have been detected. Meituan and other grocery delivery apps have also increased labor by up to 70% to help process rising orders and race to deliver goods to customers' doorsteps on the same day, according to local media.

In Shanghai, the anguish continues as officials step up containment measures despite widespread isolation, testing, and lockdowns. Over the weekend, barriers were built in some neighborhoods to isolate buildings where positive cases have been discovered, reigniting residents' resentment after weeks of being trapped inside their houses.

The financial hub remains the epicenter of China's deadliest outbreak in more than two years, dating back to Wuhan. It reported 51 fatalities on Sunday, the majority of whom were elderly, bringing the total for the current wave to 138. One hundred ninety-six individuals are in critical condition, and 23 are in serious condition.

China has dispatched nine medical teams to Shanghai's eight designated hospitals to expedite the treatment of severe cases, Xinhua reported on Sunday. The teams comprise over 360 experts with extensive experience in intensive care.

On Sunday, Shanghai reported 19,455 new cases. While daily infection rates are down, the government has not yet achieved its goal of eradicating the disease in communities.