Scotland's first minister Nicola Sturgeon has tested positive for Covid.
She said she was experiencing "mild symptoms" and would follow Scottish government guidance to work from home for the next few days.
Earlier on Friday she had held talks with Sinn Féin vice president Michelle O'Neill at her Bute House residence in Edinburgh.
Ms Sturgeon also returned from a visit to the US this week, where she had issued a warning over climate change.
She addressed the Brookings Institute and met US Speaker of the House Nancy Pelosi in Washington DC.
In a social media post, the first minister wrote: "Unfortunately I've tested positive for Covid this evening after experiencing mild symptoms.
"In line with Scottish government guidance, I'll work from home over next few days, and hopefully be back out and about later next week."
Sinn Fein confirmed Michelle O'Neill had tested negative for Covid following the meeting with Ms Sturgeon.
The party said Ms O'Neill would be tested again on Saturday "as a precaution" and would be limiting her contacts over the coming days.
Unfortunately I’ve tested positive for Covid this evening after experiencing mild symptoms. In line with @scotgov guidance, I’ll work from home over next few days, and hopefully be back out and about later next week.— Nicola Sturgeon (@NicolaSturgeon) May 20, 2022
Ms Sturgeon's positive test comes as the number of Covid-19 infections in Scotland continues to fall, according to figures from the Office for National Statistics (ONS).
The ONS estimates there were about 104,400 positive cases in the week to 13 May - about one in 45 people.
The number of hospital patients testing positive for Covid and weekly deaths are also falling.
Restrictions put in place over the pandemic were lifted as Scotland moved to living with Covid.
From 1 May, public health advice has been to "stay at home" if you feel unwell or have a fever.
People without symptoms are also no longer advised to take regular tests.
People who have Covid symptoms, a fever or are what the Scottish government describes as "too unwell to carry out normal activities" are asked to stay at home until they get better.
There can be no one in Scotland better versed in how to avoid picking up Covid. For two years Nicola Sturgeon was the face of the public health campaign to limit the spread of the virus.
She issued daily advice on hand washing, social distancing, mask wearing and even had her vaccination on camera.
It seemed to work for her. Unlike the Prime Minister Boris Johnson, the first minister managed to stay Covid-free throughout the pandemic - until now.
It is not clear if she picked it up in Scotland or on her recent travels to the United States. But as restrictions have eased and normal life has resumed, the virus has had much greater opportunity to circulate.
If Nicola Sturgeon's period of self-isolation continues until later next week, she could be stuck at home on Wednesday when she becomes Scotland's longest serving first minister.