Tougher lockdown measures have been introduced in parts of northern England after a rise in the rate of novel coronavirus transmission, raising concerns over a second wave.
Britain reported its highest number of new COVID-19 infections in more than a month on Thursday, as ministers warned more quarantine restrictions were possible.
Around 4 million people were ordered not to mix with other households in Greater Manchester, the biggest city in northern England, parts of West Yorkshire and East Lancashire, though they can still go to work.
Those breaking the rules will face a fine of 100 pounds.
"The problem with this virus is that it thrives on the social contact which makes life worth living," Health Secretary Matt Hancock told Sky. "I totally understand the human impact of this but unfortunately that is how the virus passes on."
Asked by the BBC if the UK was now entering a second wave, Hancock said: "It is not yet and we are absolutely determined to take the action that is needed."
The measures were introduced hastily at the start of Eid al-Adha.
At least one police officer was killed and dozens of people injured in Pakistan as supporters of jailed former Prime Minister Imran Khan clashed with security forces outside the capital Islamabad on Monday, officials and Khan's party said.
Israeli strikes pummelled south Beirut on Monday, Lebanese official media said, while health authorities reported 31 people killed across the war-hit country, most of them in the south.
A US judge on Monday dismissed the federal criminal case accusing Donald Trump of attempting to overturn his 2020 election defeat after prosecutors moved to drop that case and a second case against the president-elect, citing Justice Department policy against prosecuting a sitting president.
Sectarian fighting in northwestern Pakistan which killed more than 80 people last week restarted on Monday, officials said, breaching a seven-day brokered ceasefire.
Israel is moving towards a ceasefire in the war with Hezbollah but there are still issues to address, its government said on Monday, while two senior Lebanese officials voiced guarded optimism of a deal soon even as Israeli strikes pounded Lebanon.