There were 40 outbreaks of Covid-19 in schools last week, according to the latest data from the Health Protection Surveillance Centre.
An outbreak is when two or more related cases are identified in a setting. There were 34 outbreaks in primary schools, three in secondary schools and three in special schools.
The outbreaks related to a total of 191 cases of the virus. It compares to just 12 outbreaks recorded in schools the week before last - but schools had only just reopened at that stage.
In 2020, the weekly number of outbreaks in schools fluctuated widely depending on various factors, from low numbers after holiday periods to as high as 60.