DEVELOPERS have promised an investigation after the discovery of an explosive device caused the evacuation of a school near Didcot.

About 200 pupils were evacuated from Chilton Primary School yesterday after part of a Second World War rocket was unearthed at a neighbouring building site that once housed a wartime RAF munitions store.

Parents said they feared more devices could be found.

It was the second time in two months that suspect devices, from the 1940s have been discovered by contractors on the Chestnut Fields site.

About 280 houses are being built by David Wilson Homes and Bovis Homes. Spokesman Katherine Liggatt said: “Safety at the site is paramount and we will be conducting a full investigation.”

Following the discovery just after 8am, an Army bomb disposal team was called in. They carried out a controlled explosion at about 12.30pm.

Army spokesman Chris Fletcher said the operation was handled by a team from 11 Explosive Ordnance Disposal Regiment, based at Vauxhall Barracks in Didcot.

He added: “A Second World War rocket motor was found and they blew it up. The operation was finished by about 12.50pm.”

County council spokesman Paul Smith said parents were asked to pick up pupils by 1pm.

Vicky Kopp, 45, from Chilton, collecting her daughters Eve O’Shea, seven, and Thea O’Shea, five, said: “The developers should check the site thoroughly, because I’m concerned there could be more bombs.

Stefania Bartolini, 45, from Abingdon, picked up her two children, Francesco, eight, and Chiara, seven, and said: “It’s inconvenient to have to leave work early but the safety of the children must come first.

“I’m happy with the way the school has handled the situation but perhaps the developers could sweep the site to see if there are any more bombs.”

Francesco added: “I heard a bang but I wasn’t frightened.”

Andrew Coate, 42, lives about 200 metres from the school with twin daughters Freya and Alice, seven.

He said: “The last time this happened there was a huge bang and the house shook. The girls found it quite exciting but the kids in the nursery were a bit tearful.”

Last month experts detonated an unexploded RAF practice bomb on the building site.

During the war, the site was used as a bomb store by the RAF.

A number of controlled explosions were carried out in 2001 during an operation to clean up the site, when the school was also evacuated.

Ms Liggatt said the two developers jointly purchased the site in February last year from UK Atomic Energy Authority.

She added: “Before the purchase, David Wilson Homes undertook six months’ worth of ground investigations and testing by specialist ground remediation and munitions experts to ensure the site was suitable for development.”