His head clamped in the mouth of an enraged devil, Spawn concentrates; one final almighty effort and his face mutates into an armour of steel spikes which are probably fans of this and other increasingly violent comic books. Jackie Bourke reports on an unregulated sector - and asks if this nasty stuff does any harm

But there's plenty more to come. Back from Hell and hanging out with the Violator, a predatory insectile demon of lethal power, who slurps down live wriggling maggot pizza for tea, can be a bit of a drag. But it's only a film, and afterwards Keith, Glen, Derek and Lorcan, all aged 12, are beside themselves with excitement. "It was deadly, the special effects were brilliant, the start" - the one bit of plot - was boring, but Hell was great, and when he tried to bite Spawn's head off . . ." Testament to their remarkable sang-froid, the boys have the remnants of sweets and popcorn around their mouths. Spawn the movie is based on Spawn the comic, the best selling comic in the world today. Blood and guts are very in, it seems; replete with characters like Overt-Kill, the deranged cyborg murder machine, Spawn boasts a litany of Goomphs, Skraaaaaks and WHOOOMs - with Spawn himself giving it a bit of AKAKAKAKAK, and many an AAIEEE!!!!!

As with its comrades - Judge Dredd etc - if you're not being beaten to a pulp with chains, you're having your eyeball blown out through the back of your head in a sea of blood.

Kids' comics have a much-maligned history, full of bannings, censorship and condemnation. But, surprisingly, there is no authority overseeing the content and deciding what kids can and can't read. Most of the more violent American comics have a stamp of approval from the Comics Code Authority, but there is no obligation to seek this approval, and comics like Spawn don't bother.

Any sort of control is up to individual shopkeepers, who bag comics for mature readers and won't sell them to under-18s. Unfortunately, the system isn't fool-proof: recently a parent contacted E&L after she read a comic belonging to her 12-year-old. "The opening scene was essentially a snuff movie in comic form - it wasn't just extremely violent, it was pornographic," she said. "Obviously my son found it disturbing, or he wouldn't have asked me to read it."

The comic in question was an issue of The Curse of Spawn, about which the publishers advised retail outlets - a week after it went on sale. While incidents like this are relatively rare, they do raise the question: are parents aware of what their children are reading?

Kevin Lyons is the manager of Forbidden Planet, a comic-book shop on Dublin's Dawson Street. "We check comics we know have more violent tendencies, and if an issue is particularly bad, we bag it and wont sell it to minors. We also have titles which we keep on the top shelf and never sell to minors. They ask, but we won't sell. "But next thing we get their parents in asking for the comic for the kids. What can you do? Obviously we have a responsibility to ensure children don't read inappropriate material, but parents have a responsibility to check contents too."

Some parents may find the contents alarming, but research into the effect of violent comics on children shows they see them as fantasy; at worst, they might have nightmares or go off their food. In these cases, talk about what is frightening - and perhaps suggest another comic for next week. Martin Barker lectures in cultural studies at the University of the West of England, Bristol, and has written extensively about the effects of comics on children. In his book Action: The History of A Violent Comic he writes, "A lot of the argument against comics hinges on the belief . . . that the contents might damage [children's] moral capacities. "But the assumption is that either a comic like Action has no influence or a bad influence. Modern media studies have long since left behind such stupidities and now recognise other possible effects, for example, giving resources to the imagination, providing a private space away from adults, dramatising how you feel about the world, or just giving you the pleasure of reading."

Barker surveyed readers of Action (which was withdrawn from sale under pressure from concerned groups in 1976) and found that the more involved the readers were with the comic, the more complicated the effects on them. "They saw more meaning in the stories and related to them as dramas which made them think about the world."

According to Kevin Lyons, "today's comics are more violent, as are cartoons, as is the world, but the messages in kids' comics are not always negative. Comics can be educational, the artwork is often amazing, and they get kids reading."

The educational value of comics has been recognised by some libraries. "The format makes it clear to children that this isn't reality," says Patricia McKeown, a librarian at Blanchardstown Public Library in Dublin. "I have never come across a child who has been adversely influenced. "Comics absorb children, get them reading, and they can be particularly useful for children with learning difficulties like dyslexia."