Cases of Covid-19 in the south west England are "by far" the highest among 15 to 24 year olds, Public Health England warned, as the region prepares for an influx of visitors over the bank holiday weekend.
Latest figures show the south west has a rate of 461 cases per 100,000 people - the highest among the English.
Holiday hotspot Cornwall has seen a particular surge with 804 cases per 100,000 people, double the previous week, and the younger age groups are the most affected.
It follows some 5,000 infections being linked to the Boardmasters surf festival near Newquay, which took place between August 11 and 15.
Professor Mike Wade, PHE deputy regional director, said the 15 to 24 age bracket had 1,700 cases per 100,000 people.
The region has also seen small increases in those aged 60 and over testing positive for the virus. There has been a small increase in hospital admissions, but Covid-related deaths remained low.
However, PHE warned that it expected to see an influx of visitors to the South West, which covers Cornwall, Devon, Dorset, Gloucestershire, Somerset, Avon, and Wiltshire, during the bank holiday weekend.
Speaking at a briefing on Wednesday Prof Wade said: "Covid-19 has not gone on holiday. Day trippers and holidaymakers need to protect themselves and others from Covid-19."
He added that despite the rise there was "no real basis" for large events not to continue as long as “authorities are engaging effectively with the event organisers and mitigations are being put in place".