Guests at a party to celebrate a primary school's 150th birthday were horrified to discover that their car tyres had been slashed.

Six vehicles had their tyres slashed with a scalpel, which was found embedded in one tyre, as their owners were at Oaksey Primary School.

The total damage caused was £1,500, and the attack happened between 7.35pm and 11pm on Saturday.

One of the organisers of the event, Camilla Williams, said: "We are so upset that this happened, we had had a wonderful night celebrating the fact that Oaksey School is still going strong after 150 years.

"Everyone was really happy and had had a great time, and then when we came out that had happened. It really ruined the night for us.

"The slashed tyres meant a lot of extra expense and trouble for people, and there was also the problem of how they got home.

"Some people got taxis, but others were trying to change the tyre in their party clothes, and by that time it was chucking it down.

"I just don't understand why anyone would do this, it wasn't as if the event was political or controversial in some way, just a group of people who wanted to celebrate the primary school's birthday."

Anyone with any information on the crime should contact PC Martin Alvin at Malmesbury police station on (01666) 822222.