The news features horrific stories, often accompanied by horrific footage. Should children be protected from these images or told the truth?

You could not miss her last weekend: an elderly woman being helped along a Manchester street, her clothes covered in blood. My six-year-old son glanced at the pictures and remarked: "That's not real blood, is it Mum?"

I was tempted to tell him not to worry about it, to distract him with the offer of a game of football. Thomas is a mature little boy but, as his parent, I wondered whether some events are too horrific to tell him about.

Sensing my anxiety, he repeated his question, this time more insistently. "Yes, I'm afraid it is blood," I admitted, and gently told him what had happened the previous day.

He stared, shocked, at the old lady who could have been his next-door neighbour, at a baby, who could have been his sister, being carried by a security guard, and I wondered if I should have shielded him from this atrocity as I had done earlier this year with the Dunblane massacre.

Most parents, looking back over the past year, will remember the roll- call of tragedy: Oklahoma, Dunblane and Port Arthur. And many will have wanted to protect their children from any knowledge of these stories.

I found out about Dunblane when my three-year-old daughter flicked on the TV for Rosie and Jim. The announcer's face was grave. I realised too late that this was not an ordinary round-up of the day's headlines. My six-year-old, coming into the room with his reading folder, saw that something was wrong.

"What's going on, Mum?" he asked. My immediate impulse was to deny it. I switched the TV off and lied, saying that something terrible had happened far away. Professor Barrie Gunter, psychologist and teacher at the department of journalism studies at Sheffield University says that parents' desire to shield their children from shocking stories may reflect the parents' own distress. "Some stories are not just horrific in their own right, they elicit a response in parents - What if that happened to my child? - which makes the event much more upsetting."

Professor Gunter believes that decisions about viewing are best left to parents. "It depends on the age and the personality of the child, and on what is being shown." He is concerned about young children being presented with horrific images, but a simple presentation of the facts is unlikely to cause distress. "With words, children are limited by their own imaginations, but if they're presented with an image of something, they can't protect themselves."

Elizabeth Newson, professor of developmental pyschology at the Early Years Diagnostic Centre, argues that parents should not stop their children seeing the news. "I think children do have to learn to feel sorrow for the world, and to have empathy for others." But parents should avoid exposing their children to distressing stories continuously. "There is a sort of battering by media, and I would try to avoid overdoing it," she adds.

Professor Newson found that many children are affected by stories in which the victims were of their own age. "Older children are worried about muggings and rapes, but I would think that five-year-olds would have been very distressed by Dunblane because the victims were children like them, and they feel it could happen to them."

Young children may also be frightened by stories involving child abduction. Professor Newson says it is reassuring to go through all the safeguards that are there to protect them. "You know Daddy always takes you to school, and the teachers will look after you until Mummy comes."

But as Professor Newson points out, parents cannot give total reassurance. They must always sound a small note of warning: "You know you mustn't go off with strangers." She says there are dangers in telling children that news only happens "out there", a world away from their own lives. Many children are affected by burglaries, accidents and bereavements. For parents to say that these things can't happen is to risk damaging their child's trust if they do.

Naomi Atamaniuk, a teacher, has two children, Luke, aged 10, and Emma, eight. Naomi says: "My children were were indirectly involved in a fatal accident that was in the headlines. We can't pretend these things don't ever happen to people like us. What we do say is that it is very unlikely to happen."

Naomi's husband, Nicholas, an engineering worker, says they are sometimes tempted to censor the news. "We didn't really want to tell Luke and Emma about Dunblane because they may have felt their own safety was at risk, but we decided you have to tell them the truth so they don't get a mixed- up version."

It is impossible to hide news stories from children of school age. Luke Atamaniuk says he often discusses the news with his friends. "I say: `Have you heard about this?' or they tell me about something they've seen." He admits he is sometimes disturbed by the news. "I feel upset for the people. I forget about it after a day, but it's still horrible." But he thinks children should watch the news, "to know what's going on in the country". His sister Emma disagrees. "The news isn't really for children; it's for grown-ups."

If a child has experienced the death of a friend or relative, he or she can be very vulnerable to tragic news stories. Because of this, one head teacher of a primary school discusses news stories with small groups of pupils, so that the children feel secure enough to express any fears they have that were prompted by the story.

Professor Gunter stresses the importance of children learning to control their own viewing. "Parents should not switch off the television, but discuss what children watch, and introduce them to other sources of information," he says.

Some children will "switch off" from news they find very disturbing. When I could eventually bring myself to talk about Dunblane, my son did not want to listen.

Professor Newson says: "There are children who are sensitive and afraid and who don't want to talk about it. It's quite common that children are afraid of things they don't tell their parents about."

The temptation remains to ban the news, especially when the coverage is intensely distressing. But Professor Newson argues that children need to learn that the tragedies spoken of by television newscasters are real, not entertainment. That is what differentiates them from video nasties.

What is important is that parents watch with their children, when possible. "Children need to know that horrific news is a cause for enormous concern and grief," states Professor Newson. What I do worry about is some tragic news story going on in the background like wallpaper, while everyone is rushing about and chatting. That way desensitisation lies."