People in China who attended weekend protests against Covid restrictions say they have been contacted by police, as authorities begin clamping down.

Several people in Beijing said police had called demanding information about their whereabouts.

It is unclear how police might have discovered their identities....

On Tuesday morning, police could be seen in both Beijing and Shanghai patrolling areas where some groups on the Telegram messaging app had suggested people should gather again.

A small protest in the southern city of Hangzhou on Monday night was also quickly stopped with people swiftly arrested, according to social media footage verified by the BBC.

Reports also say that police were stopping people and searching their phones to check if they had virtual private networks (VPNs) set up, as well as apps such as Telegram and Twitter which are blocked in China.

One woman told news agency AFP that she and five of her friends who attended a protest in Beijing had received phone calls from police.

In one case, a police officer visited her friend's home after they failed to answer their phone and asked whether they had visited the protest site, stressing that it was an "illegal assembly".

Another told Reuters that they were asked to show up at a police station to deliver a written record of their activities on Sunday night.

"We are all desperately deleting our chat history," one Beijing protester told Reuters. "Police came to check the ID of one of my friends and then took her away. A few hours later they released her."

Police have also detained journalists covering the protests in recent days. News agency Reuters said one of its journalists was briefly detained on Sunday before being released.

BBC journalist Ed Lawrence was also held for several hours while covering a protest in Shanghai on the same night. UK Prime Minister Rishi Sunak said his detention was "shocking and unacceptable", adding that Britain would raise concerns with China about its response to the protests....