Restrictions have been reinstated for indoor gatherings in three council areas, including the city of Glasgow, after days of surging coronavirus cases.
Nicola Sturgeon said people living in Glasgow City, East Renfrewshire and West Dunbartonshire cannot host or visit other households indoors for at least two weeks.
The policy starts from midnight.
The First Minister made the announcement after chairing a meeting of the Scottish Government Resilience Committee (SGoRR) over Tuesday afternoon.
With more than 400 new Covid-19 infections recorded in Scotland in the last three days, a total of 174 of them have been found in the Greater Glasgow and Clyde health board area.
Over the last 24 hours, 154 cases of coronavirus have been confirmed in Scotland, with 66 in the Glasgow health board region.
The Greater Glasgow and Clyde and Lanarkshire areas have experienced several local Covid clusters in recent weeks including in a pharmacy, schools and one out of Low Moss prison.
The First Minister said there is especially high prevalence of the virus in three local authority areas: the city of Glasgow, East Renfrewshire and West Dunbartonshire.
West Dunbartonshire’s daily incidence rate of Covid-19 nearly 33 new cases per 100,000 people, with the figure at 22 in Glasgow and around 19 in East Renfrewshire.
That compares to a Scotland-wide average of slightly more than ten in 100,000.
Sturgeon said that in these three areas, the virus appears to be spreading “primarily as a result of household gatherings” rather than in pubs or restaurants.
As a result, households in this trio of council areas should not meet up with people from other households at either of their homes.
The only exceptions to this rule are emergencies, or meeting people you have formed an “extended household” with – a policy brought in during lockdown for people like relatives living alone or non-cohabiting partners to spend time with their loved ones.
The restrictions will be in place for at least a fortnight but reviewed after one week.
In other new measures, the whole household of a person who is identified as a close contact linked to Greater Glasgow cluster should self-isolate for 14 days.
Visiting care homes will also be restricted to outdoor visits only and hospitals will allow essential visitors only.
Sturgeon said she understands people may be frustrated with the restrictions but added it shows Covid has not gone away.
As a Glasgow resident herself, she added: “I won’t be able to have my family visit me at home and nor will I be able to travel to a different local authority, in my case Ayrshire, to visit them.”