Shanghai - China's most populous city and financial hub, Shanghai, tightened the first phase of a two-stage COVID-19 lockdown on Tuesday. The residents were told to stay indoors unless they get tested as the number of new daily cases exceeded 4,400.

The city entered its second day of lockdown with authorities dividing the city roughly along the Huangpu River, splitting the historic centre from the eastern financial and industrial district of Pudong to allow for staggered testing.

While Shanghai's caseload, 4,381 asymptomatic cases and 96 symptomatic cases for Monday, is low compared to global cases, the city has become a testing ground for China's "zero-COVID" strategy as the country tries to reign in the highly infectious Omicron variant.

Wu Qianyu, an official with the municipal health commission, told a briefing that a "clear request" had been made to residents not to leave their apartments, even to take pets for a walk or throw out trash, during "a key stage in nucleic acid testing".

Growing signs of frustration were evident on China's social media and dozens of residents flocked to the Weibo platform to seek help for relatives, with some struggling to access medical services.

Though China is sticking to its plan for crushing the outbreak, experts overseas remain sceptical about the efficacy of lockdowns in the face of a highly infectious new variant.

"It is clear from Australia and elsewhere in the world that lockdowns are simply not effective against Omicron – so expect a big wave coming," said Adrian Esterman, an expert in biostatistics at the University of South Australia.
-Reuters