Watch the report by Health Correspondent James Crichton-Smith
Face masks will become compulsory in shops and indoor spaces in Wales from Monday, the First Minister has said.
Mark Drakeford said the country has reached a threshold where 20 people in 100,000 are suffering from coronavirus.
But if the rate falls and Covid-19 is "effectively suppressed", the Welsh Government will revisit the issue, he said.
He told a press conference in Cardiff that people would continue to be encouraged to work from home where possible to limit person-to-person contact.
Local authorities will be given new powers to shut down premises and events on public health grounds, Mr Drakeford announced.
"Once again we are having to focus on tightening restrictions across Wales to prevent cases from rising even higher and prevent the problem from worsening - as we have seen elsewhere in the UK," he said.
"The new measures we are announcing today are designed to prevent a new coronavirus crisis here in Wales, not respond to one.
"Wales is not immune to the spread of coronavirus elsewhere in the UK, and as difficulties deepen elsewhere, we must expect that to have an impact here, too."
Social gatherings will also be limited to six people from next week, in an effort to help prevent the spread of coronavirus. The Welsh Government said all six people must belong to the same extended household group.
The changes come as parts of Wales have seen an increase in cases of Covid-19. The cases have been linked to people meeting and socialising with others indoors but without social distancing.
However, it has led to some disappointment and confusion for families who were getting used to being back together after lockdown. Clare Wilkinson, who lives in Caerphilly, says the changes are 'upsetting' for her family as her children's grandparents are a big part of their family.
Watch Hannah Thomas' report below:
There will be no change to the current rules, which allow up to four households to form an extended household in Wales, and no change to the rules on meeting outdoors.
Children under the age of 11 are exempt from both of the new rules and people with certain medical conditions or disabilities will not have to wear a mask.
The limit of six people meeting inside will not apply in Caerphilly County Borough which has become the first area in Wales to go into local lockdown. Restrictions in Caerphilly include a suspension on extended households meeting indoors and it is already compulsory to wear face masks in shops as the county experiences a sharp rise in coronavirus cases.
Merthyr Tydfil and Rhondda Cynon Taff have also experienced a rise in cases and there are fears they could be next to go into local lockdown.
Mark Drakeford will confirm the changes to the rules in his coronavirus briefing on Friday.