A three-month high in coronavirus cases in Scotland is “undoubtedly a concern”, Nicola Sturgeon has said.

The First Minister said she feels “a greater sense of anxiety today” than at any time “probably for the last couple of months”.

In the last 24 hours, 160 new cases of Covid-19 have been recorded, the highest total since May 16 and an increase on the 123 announced on Sunday.

It brings the total number of cases since the start of the pandemic to 20,478.

With no deaths in almost a week of people who have been confirmed to have contracted the virus, the number of fatalities remains at 2,494.

The majority of new cases are in the central belt, with 69 in the Greater Glasgow and Clyde health board area and 27 in Lanarkshire.

Speaking during the daily coronavirus briefing in Edinburgh, Ms Sturgeon said the “quite high” numbers of new cases were “partly a result of greater numbers of people being tested” and she stressed the proportion of people testing positive was still below 1%.

But she added: “The number of cases we are seeing right now is a reminder to all of us the virus is still a very real risk, it is a development that concerns me and it is one we are taking very seriously.

“We mustn’t lose sight of how important it is if we are to keep schools open, build economic recovery and retain a bit more normality in our lives that we do continue to suppress the virus and push as close to elimination of it as we possibly can.”

Ms Sturgeon added not all of the new cases were linked to larger outbreaks, saying the rise of cases in Greater Glasgow and Clyde “seems to reflect a number of small clusters, rather than one or two more significant outbreaks”.

She said an incident management team was looking at a cluster of 22 cases in Ayrshire and Arran, many of which she said “seem to be linked to indoor gatherings that took place the previous weekend”.

A cluster in Hawick in the Scottish borders had increased to 15 people, she added, with a mobile testing unit in place in the town, and there are now 188 cases linked to the 2 Sisters food processing plant in Coupar Angus.

On Monday, Scotland took more steps out of lockdown, with the opening of gyms and indoor swimming pools and the resumption of youth groups such as Cubs and Brownies and mother and baby groups.

The First Minister said “many people” had been looking forward to gyms and pools reopening, adding that the move would be a “major relief for people who work in the leisure centre”.

She added: “The reopening is a further welcome step in getting back to normal, it is important for wider health and wellbeing.

“But it also obviously brings risks, there is no getting away from that, and that is why we have delayed this until now.”

Ms Sturgeon added: “The figures we are seeing just now for new cases demonstrate very clearly that this virus is still present across the country, it will spread rapidly if it gets the chance.”

She warned Covid-19 was still “immensely dangerous for some people” and urged people to “continue to make sure you are not doing anything that gives the virus the chance to spread”.

Concluding the briefing, Ms Sturgeon issued a plea for people to “think very carefully about how you’re living your life at the moment” as she revealed anxiety about the “fragile” state of coronavirus suppression.

Reflecting on the past seven months, she said: “There have been some really dark moments along the way since the start of March and, more recently, there have been moments of greater hope and optimism.

“I have always tried to be frank with you about my assessments and feelings about the situation that we are in, which is why I feel able to say to you today – and feel that it is important I say to you – that I feel a greater sense of anxiety today than I have done any time probably for the last couple of months.

“We are in a fragile position; we have substantially lifted the lockdown restrictions but in doing so we’ve allowed this virus opportunities to spread.”