BEIJING (Bloomberg): China has built a massive Covid-19 isolation centre made up of row upon row of temporary buildings over a vast expanse in the country's south, as officials continue to treat the virus as a threat that needs to be stamped out.

Drone footage shared on Douyin, Tiktok's twin service in China, shows scores of what appear to be pre-fabricated structures similar to shipping containers lined up in a clearing surrounded by forest.

Several social media users said the video showed a Covid-19 quarantine facility in Guangan city, Sichuan.

Under China's Covid Zero policy, everyone infected with the virus and all their close contacts must go into centralised isolation facilities for at least a week.

Provinces were told in March to build two to three of the so-called makeshift hospitals as a way of quashing transmission in the community.

Construction on the Guangan city site, which can house 14,000 people, started in April, according to a local Covid-19 mitigation official who declined to be named as per government rules.

It's part of a broader plan to provide 20,000 isolation beds across three sites that span 1.3sq km, according to the state-run China News Service.

At that size, the facilities could encompass roughly 240 American football fields.

The footage was originally shared Sept 17 on Douyin by a user called Datang Shiye, who didn't reply to questions from Bloomberg News.

Government officials also didn't respond to requests to verify the video.

Commentary from those sharing the footage ranged from appreciation that the authorities were preparing for future outbreaks, to jail comparisons.

The Guangan facility has been receiving people with Covid-19 and their close contacts from Neijiang, a city about 2.5 hours drive away, according to residents who posted about the experience on social media.

The district where the centre is located in Guangan was locked down on Monday, although the city hadn't reported any infections.

Sichuan's caseload has been easing.

There were 55 infections reported province-wide for Tuesday, down from a peak of 260 at the end of August when most were found in the capital Chengdu.

The outbreak led the city of 21 million people to lock down for two weeks to contain the spread.

Most movement restrictions were lifted on Monday.

While the Guangan camp is vast, Shanghai erected an isolation facility that could accommodate even more people during its Covid-19 outbreak in the spring.

The city's National Exhibition and Convention Centre, a cavernous building typically used for auto shows and trade fairs, was temporarily converted to accommodate 40,000 beds in April.

The facility operated for 53 days and hosted 174,000 residents before it closed in May.

The southern metropolis of Guangzhou has been running a 5,000-bed quarantine centre mainly for international travellers returning to China.

While most of the world is dismantling pandemic barriers, China still requires people entering the country to quarantine for 10 days.

President Xi Jinping has tied his rule to the Covid Zero strategy, saying China can't afford the deaths that other countries have seen when living alongside the coronavirus.