Enhanced testing for coronavirus will take place following a rapid rise in cases in part of Norfolk.
People over 16 in Hemsby, Ormesby, Somerton and Winterton are being urged to get tested for the virus even if fully vaccinated.
Cases for the Great Yarmouth area in the week to 14 July stood at 459 per 100,000, compared to 175.2 the previous week, Norfolk County Council said.
A large number of the 162% increase in cases were found in the four parishes.
In Norfolk as a whole, for the same period, there were 222.5 cases per 100,000, compared to 324.8 per 100,000 in the East of England and 426.1 per 100,000 in England.
It said it was important for people who were fully jabbed, or who were not showing symptoms, to still take the test.
Mobile testing units will be offering PCR testing, with home test kits delivered to those who have been identified as clinically extremely vulnerable.
They will also be available at venues such as pharmacies and libraries.
The testing is being aimed at those people living and working in the area rather than visitors or tourists.
Diane Steiner, Norfolk's deputy director of public health, said one in three people had no symptoms but could still be passing the virus on.
"We know cases are generally rising across the whole of the UK," she said.
"But not everyone has been vaccinated and even with a double jab, it is still possible to contract the virus.
"And we are seeing a rise in the number of people requiring hospital treatment across the county."
Legal restrictions on everyday life were removed across the whole of England on Monday.
The average number of daily confirmed cases has been rising sharply in recent weeks.
A further 46,558 confirmed cases in the UK were announced on Tuesday.
The rise in cases is being driven by the Delta variant, according to the government.