The number of daily coronavirus cases in the UK has shot up to almost 2,000 per day.
There has been a 53 per cent rise in one week, according to a symptom-tracking app.
King's College London used data from more than four million people who report if they have Covid-19 symptoms.
It flagged six new coronavirus hotspots, with three added for the first time.
East Renfrewshire, Scotland, leads the list, with West Lothian in 10th position.
Ards and North Down in Northern Ireland are new to the list, with Neath Port Talbot, Nottingham and Tameside back on after being taken off.
However, no area in the south or east of England including London is on the list.
According to estimations, 22,040 people currently have Covid-19 symptoms in the UK excluding care homes, up from 18,340 the week before.
Tim Spector, a professor at King's College London, who leads the app's research, said: "While with increased economic activity and travel we are seeing the numbers starting to creep up again, it is good to see that when numbers start to rise, areas like around Glasgow are taking swift action to help stop the situation spreading."
On Thursday, residents in Leeds were warned of potential new coronavirus measures after an increase in cases.
Council leader and chair of the outbreak control board, Judith Blake, said: "This is a pivotal moment in our efforts to control the spread of the virus in Leeds and to keep our city open.
"Nobody wants to see further restrictions on life in Leeds and we want to assure everyone that we're doing absolutely everything within our power to avoid that happening.
"But the harsh reality is that if our infection rate continues to rise as it has been, we will be left with no alternative.
"With that in mind, now more than ever we need a collective effort from the people of Leeds who have shown so much resilience and civic pride throughout this crisis.
"It's up to us all to keep our families, friends and neighbours safe and to play our part in keeping Leeds's recovery going."