FIREFIGHTERS are probing the cause of a blaze which damaged a marquee being packed away after this week's St Mellons Show.

Organisers of the agricultural show - held on Wednesday at Newport's Tredegar House - were hit by a fire which broke out at 12.22pm yesterday. Three sides of the marquee, used in the one-day show, were burned up.

A South Wales Fire Service spokeswoman said the cause of the blaze is being investigated, but it is being treated as a suspicious fire.

Police say the fire was out when they arrived and had caused minor damage to the marquee. A Gwent Police spokeswoman said further investigations into its cause will be carried out by the fire service.

Show organisers say they believe that youths were behind the attack. Show organiser Karen Meakin said: "The police had to come back and forth here on Wednesday night because of youths; we did have a problem with them.

"There were loads of people around yesterday when the fire was started. We all rushed to help put it out.

"The roof of the marquee is still standing and so are the posts, but three sides have gone.

"It is a shame to end on that note, because this year's event was a great success and we had around 12,000 visitors, and Tredegar House has been a fantastic venue."

The agricultural show featured displays, trade stands, dog shows, rabbit shows and a children's fun fair.