Public health chiefs have issued a warning after a school was forced to close when a third of its pupils were struck down by a suspected winter vomiting bug.

The West Yorkshire Health Protection Unit said anyone with symptoms such as vomiting or diarrhoea should stay away from school or work for 48 hours after their symptoms have stopped to prevent the spread of the norovirus bug.

The warning comes after 135 pupils out of the 450 at Oakworth Primary School in Keighley went home with symptoms of the infection. Staff are also understood to have been affected.

A letter to parents on the school’s Twitter account stated: “The Health Department has given us advice which we have acted on immediately.”

The school was closed for a deep clean last Friday, but has since re-opened.