While lockdown is confining around 26 million people in China’s largest metropolis of Shanghai, the coronavirus outbreak is still “extremely grim”, as per a city official on Tuesday.

State media quoted Gu Honghui, the Director of Shanghai's working group on epidemic control, as saying that the outbreak in the city was “still running at a high level."

“The situation is extremely grim," he added.

More than 10,000 health workers from around the country, including 2,000 from the military, were sent to help in the city, as most of eastern Shanghai remains locked down.

According to Gu, officials will be reevaluating preventative measures after analyzing the test results of all city residents.

“Before that, citizens are asked to continue following the current lockdown measures and stay in their homes except for medical and other emergency situations,” Gu said.

Shanghai had launched on Monday, March 28, a phased lockdown that failed to end on Friday, April 1, as was expected, due to the more than 73,000 positive cases already reported since the resurgence of the highly contagious Omicron in March.

China reports record-high daily infections, new variant found in Suzhou

On Sunday, 13,146 local COVID-19 cases were reported in mainland China, 11,691 cases of which are asymptomatic. The number has been the highest since the latest outbreak, which has infected more than 100,000 people. 

The region that is most severely hit is Northeast China's Jilin Province, and the curve has not seemed to be declining. The mass majority of cases in China have been found in recent days where a new Omicron variant was discovered, in East China's Jiangsu Province, neighboring Shanghai.

438 cases were confirmed particularly in Shanghai on Sunday, among which 7,788 are asymptomatic, as per Chinese Vice Premier, Sun Chunlan, who made an official visit to the city on Saturday to help battle the virus.

Shanghai faces severest COVID-19 challenge

Authorities in China's biggest city, Shanghai, have begun a new round of nucleic acid testing for key regions as part of preventive measures against the COVID-19 pandemic.

This came as the city witnessed "the severest and complex challenge since epidemic prevention and control began on a regular basis," Wu Jinglei, director of the Shanghai Health Commission, pointed out at a press conference on March 23. 

According to the city's health commission, Shanghai reported four local COVID-19 cases and 977 local asymptomatic infections.

The Global Times newspaper said that "Shanghai has renovated two indoor stadiums as quarantine sites for mild COVID-19 cases and asymptomatic carriers."

In addition, authorities have required "14 days of centralized observation and seven days of self-health management" for close contact with infected people.

Wu Fan, a leading expert with Shanghai's COVID-19 medical team, stressed that "the city insists on a scientific, targeted and dynamic zero-COVID policy, mentioned the newspaper.