Shanghai residents frustrated with the latest Covid lockdown measures have taken to screaming from the windows of their apartment blocks, according to several viral videos on social media. 

China's largest city has been under lockdown since April 5, when Beijing ordered a complete shutdown as part of its "zero Covid" policy. 

The strategy has seen its 25 million inhabitants locked down in phases, inciting complaints of food shortages and clashes with health workers. As part of the mandatory regulations, residents have had to repeatedly take Covid tests and are prohibited from leaving their homes "for any reason" including to get food. 

One Twitter user posted a clip online that he said was taken by the father of his close friend who reported that "people (are) screaming outside of their windows after a week of total lockdown" because they "can't even step outside their apartments". 

In the footage, many screams can be heard from the windows of nearby apartment buildings. 

"It's Shanghai, everyone is screaming, started with a couple now everyone is screaming, after a week of lockdown, something is going to happen, no one knows when this is going to end," the man says in the clip, according to an interpreter. 

The government has been dropping rations and people are using delivery services, though even those services are curtailed due to the restrictions. 

China is sticking fast to a policy of snap lockdowns, mass testing and travel restrictions to staunch the spread of the virus even as Shanghai's daily case numbers have spiralled under an Omicron-fuelled wave. 

The business hub reported a record 24,943 new infections on Sunday – mostly asymptomatic, accounting for over 90 per cent of the national total. 

Authorities have readied tens of thousands of new beds in over 100 makeshift hospitals as part of a policy of isolating every person who tests positive for the virus – whether or not they show any symptoms. 

Locals have begun to chafe at lockdown restrictions with many taking to social media to vent anger at food shortages and heavy-handed controls – including the recent killing of a pet corgi by a health worker. 

An unpopular policy of separating infected children from their virus-free parents – now softened – also triggered a rare show of public anger this week. 

But officials are not budging on their zero-tolerance approach. City health official Wu Qianyu said during a Sunday press conference the city "would not relax in the slightest". 

Major online delivery platforms said they would bolster food stocks and draft in thousands of drivers to strengthen the supply of basic goods. 

In an interview with a local news outlet on Saturday, Zhang Wenhong – a top doctor in Shanghai's pandemic fight – acknowledged the impact on the healthcare system but said "realising dynamic zero … will help to resume normal medical order as early as possible".