Testing will take place at Dogsthorpe Community Centre on Poplar Avenue, Dogsthorpe, from tomorrow until Sunday.
In addition, the testing facility at Gladstone Park Community Centre will now be in place until the end of the week (Sunday 26 July).
Both sites will be available for testing from 10am until 3pm each day.
People with symptoms can just turn up and have a test. To avoid having to wait, people are able to book a test by visiting www.nhs.uk/conditions/coronavirus-COVID-19 Those unable to access the internet can call 119 to book a test.
Key workers can log on to the self-referral portal www.gov.uk/apply-coronavirus-test-essential-workers. They will be offered a drop-down list of local options for testing including nearby mobile units.
Dr Liz Robin, director of public health for Peterborough City Council, said: “We want to make it as easy as possible for people with coronavirus symptoms to get tested and that is why we have two mobile testing sites available this week.
"The more people we can identify as having the virus, the easier it will be for us to provide support to those people to help them to isolate and break the chain of onward infection, thus protecting their friends and family.
"This will likely lead to an increase in identified Covid-19 cases over the coming fortnight, and potentially an increase in Peterborough’s national ranking for number of cases per 100,000 population.
“Please, if you have symptoms of coronavirus – a fever, new continuous cough or a loss or change in sense of smell or taste – please book an appointment for a test and self-isolate immediately. You will also have the option to attend the permanent testing site at Peterborough Showground.
“If you follow the rules and test and isolate if you have symptoms, the safer it will be for your family and friends and the better chance we have of avoiding a second stage of lockdown.”