Scuffles broke out as anti-lockdown protesters marched through central London on Saturday, defying police warnings for them to stay away due to coronavirus restrictions.

Police said they had made 36 arrests, most for COVID regulation breaches, after up to 10,000 people gathered holding banners with slogans such as "Stop Destroying Our Kids' Lives" and "Fake Pandemic". Crowded close to one another, protesters also set off flares.

Under England's coronavirus rules it is unlawful for groups to gather for the purpose of protest, but opposition to such measures has grown this week, not specifically related to anti-lockdown demonstrations.

Police were criticised for using heavy-handed tactics to break up an outdoor vigil for 33-year-old Sarah Everard on March 13. A police officer has been charged with her kidnap and murder.

More than 60 British lawmakers wrote to interior minister Priti Patel on Friday calling for protests to be allowed during lockdown and saying that attending a demonstration should not be a criminal offence.

"We call on you to expressly exempt protests from restrictions on gatherings," lawmakers, including Conservative Member of Parliament Steve Baker and Liberal Democrat leader Ed Davey said in the letter, which was organised by campaign groups Liberty and Big Brother Watch.

There were three consecutive nights of protest in London earlier this week, fuelled by the police reaction to the vigil for Everard, and anger over government plans to tighten the law on demonstrations.

The interior ministry, known as the Home Office, said when asked about the letter that the COVID-19 stay-at-home order remains in place until March 29, and once it ends protests can resume subject to agreeing to respect social distancing.

"While we are still in a pandemic we continue to urge people to avoid mass gatherings, in line with wider coronavirus restrictions," a spokeswoman said.

Police said people breaching COVID-19 regulations could face fines or arrest. Reuters