Nursery pupils had to be sent home from school after vandals smashed all the windows in their classroom.

The incident at St Oswald's CE Primary School is the latest in a series of stone attacks in which windows and doors have been broken. And the vandals have even tied notes to the stones which state: "I did this" and "We'll be back".

Headteacher Lynn Wiggan said: "We arrived in the morning to find 16 windows and the door smashed, even though they are double glazed. They must have had large stones and really battered the windows.

"We had to close the nursery because there was broken glass everywhere. To walk in and see all that was just heartbreaking.

"Our nursery children crawl about on the carpet and we couldn't let them back in there until every piece had been moved."

The vandalism is even more distressful because the school has recently moved from Little Horton Lane to Cross Lane in Great Horton following the reorganisation in Bradford. The buildings are being refurbished and all the windows were new.

Mrs Wiggan said: "Everything was just starting to look nice. But it will cost £1,000 to replace the windows which the school will have to pay for."

Parents have decided to start fundraising to buy security cameras in the hope this will stop the vandalism.

Parent Beverley Naylor has two children at the school and three nephews and nieces whom she takes to school every morning.

She said: "The school used to be a bit of a dump and then they spent money doing it up but it just keeps getting broken. They ran out of money needed for CCTV cameras and the parents are trying to raise money but we shouldn't have to do this."

Mrs Naylor, of Marsh Lane, said she dreaded taking the children to school every morning as she didn't know what state it would be in.

Thieves have also targeted the school and electrical equipment has been stolen.

Mrs Wiggan said: "There are builders on site most of the time so doors are open so a sneak thief could quite easily walk in. Someone is taking advantage of this situation."

A police spokesman said: "We are concerned about the number of recent incidents at the school and will not tolerate ongoing vandalism. These incidents are being investigated. We would appeal to anyone who has any information about who is responsible to contact us.

"We work closely with schools and the local education authority to combat these problems and we are working with this school to try to help improve the security arrangements and crime prevention measures."