The UN children's agency has launched a hard-hitting ad campaign, involving cartoon legends the Smurfs being blown away in a sudden air strike.
The film, which aims to raise money for former child soldiers in Africa, is being shown on Belgian TV.
A spokesman for Unicef Belgium said it had departed from previous policies on advertising in order to shock people, and that this tactic was working.
Unicef said the ad should only run late at night to avoid scaring children.
The 20-second clip opens with the Smurfs happily dancing and singing their theme song accompanied by birds and butterflies.
But then planes appear which drop bombs on the idyllic scene, setting fire to the blue-skinned characters' houses.
One character, Smurfette, is killed and others run for cover while a baby is left crying in the middle.
The ad finishes with the message: "Don't let war affect the lives of children."
The ad featuring the Smurfs - who were created by Belgian cartoonist Pierre "Peyo" Culliford in 1958 - is only running in their home country.
But Unicef Belgium spokesman Philippe Henon said reactions to the campaign were coming from across the world.
"Seventy per cent are positive, but with some people we are having a hard time explaining why we are using this," he told the BBC News website.
People were not easily motivated to help humanitarian causes, and Unicef wanted to change this by making a stark link between happy childhoods and the horrors of war, he said.
In a report released last year, the UN said fighters under the age of 18 were used in 22 conflicts between 2001 and 2004.
Unicef's Belgian campaign is focused on Sudan, as well as the two former African colonies of Burundi and the Democratic Republic of Congo.