LONDON • British Prime Minister Boris Johnson slowed the easing of lockdown measures yesterday, warning that the resurgence of coronavirus across Britain must be stamped out.

Mr Johnson postponed plans to allow high-risk venues such as casinos, bowling alleys and ice rinks to reopen today. They will have to wait at least another two weeks, he said.

He also extended regulations to make face coverings compulsory in more indoor settings, such as museums and cinemas, and said police will enforce compliance from Aug 8.

While the Prime Minister insisted he does not want to reimpose a "full national lockdown", he said it is vital for the public to obey the rules to avoid more drastic action.

"Our assessment is that we should now squeeze that brake pedal in order to keep the virus under control," he said in a televised press conference yesterday.

"We cannot be complacent. I won't stand by and allow this virus to cause more pain and more heartache in our country."

Mr Johnson's announcement came after ministers rushed late on Thursday to reimpose restrictions on more than four million people in northern England, including Manchester, barring members of different households from mingling indoors.

The Prime Minister said the prevalence of the virus in England is at one person per 1,500, up from one in 2,000 at the start of last month.

"We can't afford to ignore this evidence," he said. "Unless people follow the rules and behave safely, we may need to go further."

New data published by the government yesterday shows that the so-called R number, representing how many people each new Covid-19 patient infects, may be above the critical threshold of 1 in the north-west and south-west of England.

Beyond that level, transmission can begin to take off exponentially.

BLOOMBERG