LONDON—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 made 13 arrests 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 …