Leighton Primary School in Peterborough will be closed for a third day tomorrow (Friday) following the discovery of an infestation of mice.
The school, in Orton Malbourne, has been shut since Wednesday.
Pest control experts have spent the last two days inspecting the school to find out how big the problem is.
It is hoped children will be able to return to class on Monday.
Hayley Sutton, headteacher at Leighton Primary School, said : “We’ve written to parents this afternoon to tell them that the school will remain shut tomorrow.
“Over the last few days we have been working with pest control experts and the council’s environmental health team to deal with the issue. During this time a number of mice have been discovered in the school.
“As soon as we receive the all-clear we will need to thoroughly clean the school before we can let pupils return. Pest control experts will be back on site tomorrow morning to assess the situation then.”
A majority of mice have been found in the classrooms, with only one in the school kitchen.
Pest controllers have been using sticky traps to catch the rodents - and once the last mice have been caught, a deep clean of the school will take place.