Terrorism has been a focus for some fringe productions

They range from high drama to stand-up. An opera looks at suicide bombers and has questioned the war on terror.

Several shows have looked at unfolding events in Abu Ghraib jail, others have examined US foreign policy and a musical has been produced.

Dr Cynthia McVey, of Glasgow Caledonian University, said laughter was a way of dealing with stress.

"Certainly laughter has a place in recovering from stress and stress-busting," she said.

There's always an audience if you've got something of an ooh-ah factor Cynthia McVey Psychologist

"To that extent, although some people might not understand it, it might be helpful."

Dr McVey, an expert in group behaviour, added: "There's also a sense of spirit, a sense of 'we'll show the terrorists it doesn't matter what they do, we can produce a musical and we can laugh.'

"There's always an audience if you've got something of an ooh-ah factor and if you've got terrorism in the Fringe, you'll have something of that."

Critics have predicted it is likely that political, "real" issues are likely to feature in the rest of the capital's summer festivals.

Writers and directors believe the arts should tackle every issue

Davey Anderson, writer of the show Snuff, said his work about tensions between communities in a Glasgow tower block had become even more relevant in light of recent events.

He said: "The piece started of as an imagining of terrorism nearer to home and it has become more topical.

"Terrorism has become closer to home and how we respond to it needs to become more complicated and more sophisticated."

The issue also get tackled across the Festival programme in everything from comedy to musicals.

Jessica Beck, director of Terrorist the Musical, said: "I think comedy helps get an open discussion and get a lot of things across and provoke people to talk about things.

"With very serious dramas, people tend to shy away from that."