Many children are exposed to continuous war coverage at home, as parents leave TV sets on from early morning to late evening. Headteachers fear that a constant diet of war images may have a disturbing effect on their pupils.
"The messages are graphic, stark and upsetting. We would prefer children to be allowed to get on with their lives," said Ian Poulter, head of Alderman Blaxill school, in Colchester, Essex.
Many schools are trying to avoid detailed discussion. But heads are unable to censor the images that appear in children's homes.
The effect can be profound among children with relatives in the Gulf. More than half the pupils at Shipton Bellinger primary in Hampshire have parents in the military, many serving in Iraq.
Derek Atkinson, the head, has asked parents not to allow 24-hour news in their homes. "Kids have a morbid fascination with news images. They see a market bombing and think, 'that could be my dad'," he said.
All-news channels, he added, presented unconfirmed, often contradictory reports. Few children are able to cope with the tension that this creates.
"My advice is to leave the news until it's a bit more sanitised, summarised in bullet-points in the evening news," he added.
For schools with a large multicultural intake, news coverage also takes on an immediate relevance. Sue Seifert, head of Montem primary, in north London, says one Iraqi refugee pupil found footage of a bombed market-place particularly disturbing.
She said: "Her aunt is in Iraq. Seeing these pictures really upsets her, because she has no contact, and no idea where her aunt is."
Gargi Bhattacharyya, lecturer in cultural studies at Birmingham University, said some children cannot distinguish war footage from violence in computer games.
"There are battle plans and new technology. You're put in the position of coalition troops, firing. Children want a hit so they can go to the next level of the game," he said.