A COVID-19 cluster in England's worst-hit area has been linked to a nightclub, according to health bosses.
Lincoln currently has the highest case rate in the UK with 653.6 cases per 100,000 people - more than Northern Ireland, which has by far the highest case rate out of all the UK regions at 486.7.
It came as new cases increased by 83% to 649 in the week to 29 July.
But the Wharf and University district, which is a hotspot of cafes, restaurants and nightclubs, recorded a rate of 1,140.
Natalie Liddle, from Public Health Lincolnshire, told the BBC that the majority of cases were in people aged under 30.
She said: "We are currently managing a cluster of outbreaks in and around Lincoln - and we've seen a particular increase in cases linked to the night-time economy."
"We are particularly dealing with one large outbreak at the moment that has impacted a large number of people."
It comes as the UK vaccine rollout has slowed down due to a slow uptake among younger age groups.
Watch: Proof of full vaccination condition of entry to nightclubs from end of September
Nearly eight months since the first Covid-19 vaccine was given in the UK, more than three million 18 to 29-year-olds have yet to take up the offer of a first jab.
Vaccination rates vary across the four nations of the UK, but take-up among younger age groups remains consistently lower than the equivalent figures for older groups.
Liddle urged everyone to get the jab, adding that it was more important than ever since all social distancing, testing, face coverings and vaccination rules for nightclubs had been scrapped.
Meanwhile, Boris Johnson announced last month that people attending nightclubs and other large venues where crowds gather would be required to be fully vaccinated from the end of September.
Elsewhere, cases in most parts of the county have fallen with North East Lincolnshire seeing one of the sharpest drops as case rates decreased by nearly 50% in the week to 29 July.
But on Tuesday, the UK recorded another 138 deaths - the highest daily toll since
Watch: UK records another 138 deaths as highest death toll since 17 March