A local lockdown in the county borough of Caerphilly will not be lifted until October “at the very least”, Wales’s health minister has said.
People will not be allowed to enter or leave the area without a reasonable excuse after the restrictions come into force at 6pm on Tuesday.
Everyone over the age of 11 will be required to wear face coverings in shops – the first time this will be mandatory in Wales.
Meetings with other people indoors and extended households will not be allowed, while overnight stays have also been banned.
The measures follow a spike in cases in Caerphilly county borough, where the Welsh Government says there have been 133 new Covid-19 cases over the past seven days.
This is equivalent to a rate of 55.4 cases per 100,000 – the highest rate in Wales and one of the highest in the UK.
Health Minister Vaughan Gething told BBC Radio Wales that the rate is “expected to rise” after community testing in the area on Saturday showed a positivity rate of 4%.
“Even a week ago, we comfortably had the lowest rate of coronavirus of any of the UK nations,” Mr Gething told the BBC.
“We’re now in a position, a week later, where we’ve seen a significant spike in activity.
“That shows that coronavirus, over the course of a couple of weeks, can build up very quickly.
“If we don’t address the issue in Caerphilly, we’ll see wider community transmission within the Caerphilly area, but that will spread to other areas as well.
“The reasons for the local lockdown are a spike in transmission that, if left unaddressed, will go out of control.
“We’ll see more people get it, we’ll see more people go into hospitals, being seriously unwell, and it will then have national consequences.”
Mr Gething said a “significant cause” of the virus spreading was social distancing breaking down, with people socialising in each other’s households in larger numbers.
He told the BBC that pubs and bars would remain open in the Caerphilly area, as significant transmission is not taking place there.
The lockdown measures, which are being enforced by the local authority and police, will be reviewed every couple of weeks.
“But the evidence and advice that I’ve had from our scientific and medical advisers is that we’re unlikely to see a significant change until two to three weeks, to see the impact these measures are having,” Mr Gething said.
“So we’re in it for several weeks, at least in Caerphilly.”
Asked if that meant the local lockdown would remain in the area until October, Mr Gething replied: “Yes, at the very least – I can’t overstate the seriousness of the position that we’re in.”
Community testing was introduced in Caerphilly over the weekend, with 450 people tested on Saturday. Of these, 19 had the virus.
A similar number of people were tested on Sunday, with results expected shortly.
Travel restrictions included in the lockdown mean people cannot enter or leave Caerphilly County Borough Council area without a “reasonable excuse”.
This includes work, if people are unable to work from home, as well as making a compassionate visit to a loved one or to provide care.
People will only be allowed to meet others outdoors, with indoor meetings and gatherings restricted.
Caerphilly Council has already introduced measures such as suspending care home visits, and introducing weekly testing for care home staff, in response to the increase in cases.
On Monday, Public Health Wales reported the highest number of positive Covid-19 cases in months.
From 6pm Tuesday, the following restrictions will be in place in Caerphilly County:🔺Indoor meetings and overnight stays will not be allowed🔺Mandatory face coverings indoors, including shops, for everyone over 11🔺No travelling to/from the county without a reasonable excuse pic.twitter.com/wf4F4MQIoF
— Welsh Government (@WelshGovernment) September 7, 2020
It said that a further 133 people had tested positive for coronavirus, representing the highest daily figure since June 27, when 140 cases were reported.
There were no further deaths in people with coronavirus, with the total in Wales since the beginning of the pandemic remaining at 1,597.
Numerous schools have been affected by coronavirus since the start of the autumn term, including one class of 21 pupils at a primary school in the Caerphilly area being told to self-isolate for 14 days.