Rows upon rows of metal boxes to house suspected COVID-19 patients, lines of buses taking people to quarantine camps were seen in a set of nightmarish social media videos from China. The scenes, which seemed straight out of a dystopian movie, are among the several strict preventive measures the country is taking to check the spread of COVID-19.

China has imposed several draconian rules on its citizens under its "zero Covid" policy, placing millions under quarantine even as Beijing prepares to host next month's Winter Olympics.

People, including pregnant women, children and elderly, are being forced to stay in these crammed boxes furnished with a wooden bed and a toilet - for as long as two weeks - even if a single person tests positive in their locality, reported Daily mail.

In several areas, residents were told just after midnight that they need to leave their homes and go to the quarantine centres, it said.

In China, mandatory track-and-trace apps mean close contacts are usually detected and quarantined quickly.

Around 20 million people are now confined to their homes in China and are banned from leaving their home even to buy food, according to the report.

This comes days after the distressing case of a pregnant Chinese woman miscarrying after a strict lockdown delayed her access to medical treatment. The incident reignited debate over the limits of China's zero-tolerance approach to COVID-19.