Carnforth’s North Road Primary School was forced to close after five members of staff and more than 40 children came down with a sickness bug.
The school issued an urgent notice for parents to collect their children on Wednesday morning after the bug swept through the school, initially affecting five staff members and 45 children.
Parents were asked to collect their children as soon as possible.
The school was expected to remain closed at least for today, Thursday, while a deep clean was undertaken.
Parents were also asked to keep any affected children off school for 48 hours clear after having the bug.