NICOLA Sturgeon has announced tighter coronavirus rules restricting gatherings to a maximum of six people.
The First Minister said the new rule applies in all locations, including homes, bars, restaurants, gardens and parks.
It comes after similar measures were introduced by Prime Minister Boris Johnson in England.
A maximum of six people from two households will now be allowed to meet, with limited exceptions for organised sport, worship, weddings, civil partnerships and funerals.
Children under 12 are not counted within the limit.
The new rules come into force from Monday, although Ms Sturgeon asked Scots to start abiding by them immediately.
She said the pandemic is accelerating again, albeit from a low base, with the R number or reproduction rate of the virus now possibly as high as 1.5.
The First Minister announced a three-week delay in further reopenings because of this rise in cases.
This means theatres and music venues are not now set to reopen until October 5, rather than September 14.
The go-ahead for indoor sports courts, certain outdoor and indoor live events and the limited reopening of football stadiums has also been pushed back until this date.
Face coverings will now be mandatory in indoor hospitality venues for staff and customers when not eating and drinking.
Ms Sturgeon said Scotland is not likely to enter the fourth and final phase out of lockdown “for some time yet”.
She said there were 161 new coronavirus cases in the last 24 hours, with 65 of these in the Greater Glasgow and Clyde area, 46 in Lanarkshire, 12 in Lothian and eight in Ayrshire and Arran.
The remaining 30 were spread across eight different health board areas.
No confirmed Covid deaths were registered.
Residents in Glasgow City, East and West Dunbartonshire, Renfrewshire and East
Renfrewshire are still asked not to visit other households due to a jump in cases.
Ms Sturgeon said approximately 96% of businesses in Scotland are now trading again, while children are back in school.
She said: “People are meeting up more, going out more, and travelling more. All of that is positive.
“But as we released ourselves from lockdown, we also released the virus.
“We gave it more opportunities to spread and so it was always likely that we would see a rise in cases.”
She added: “Taking account of all the most up to date information we have, it is the Scottish Government’s judgement that we cannot at this stage risk the new opportunities for transmission of Covid that reopening further services and facilities would entail.”
The First Minister said the decision to delay further reopenings had not been taken lightly.
She said: “But right now, given the rise in cases, it’s the only responsible decision we can reach.”
She added: “However, I want to be clear that while we still face a battle to get and keep Covid under control, we are in a stronger position than earlier in the year.”
She said it is “vital to do everything we can to stop cases rising further before winter”.
Ms Sturgeon said: “I know that making those choices – keeping our distance from friends, staying in small groups indoors, washing our hands regularly – gets harder and more tiresome as time passes.
“But they are more important now than they have been for months.”