BOGOTA, Colombia (AP) _ In one television ad, actors portraying masked gunmen pull passengers marked for murder off a bus. In another, guerrillas and soldiers spray gunfire at each other in a forest.

``Without you, it's impossible to stop this war,'' a somber voice declares at the end of each 30-second commercial.

Unable to end a decades-old rebel war, the government of one of the world's most violent countries is trying an unusual tactic: national TV ads that promote peace with images of violence.

Old symbols of peace _ the dove, the white handkerchief _ have failed to jolt Colombians out of their apathy toward a conflict that claims thousands of lives every year, said a spokeswoman for the government's chief peace negotiator.

``The idea is to show the reality in a crude way because that's how it is,'' said Maria Alejandra Villamizar. ``We have to reach people who don't feel affected.''

A government panel, concerned about the violent content of the commercials, delayed their broadcast for several days. The ads, which cost $85,000, were first shown last weekend and will air for two months.

One of the five ads depicts the moments before a massacre in Uraba, a banana-growing region in northwest Colombia where leftist rebels battle the military and landowner-backed private armies.

In the ad, shouting gunmen in ski masks board a bus on a road lined with banana trees. They grab screaming victims. One man, his hands bound behind his back, is shoved to the ground.

Another commercial shows a soldier training his gun on a helpless rebel. ``Juan?'' the soldier says as he recognizes his foe.

Some Colombian families have relatives in both the military and rebel groups. One high-profile example is Carlos Pizarro, a former rebel commander and son of a navy admiral assassinated in 1990 while running for president.

``At Christmas, there are truces when they meet,'' said ad director Ivan Benjumea. ``If they come across each other at any other time, they kill each other.''

Some actors easily handled guns in the commercials because they are former rebels or served in the army, Benjumea said.

The government hopes the ads will shock Colombians into publicly demanding talks between the warring parties. Rebels, who say they fight for the poor, lack wide political support.

Some Colombians doubt the ads will slow violence in the country of 37 million. There were more than 26,000 murders in 1996, most unrelated to the rebel war.

``Maybe they'll make us reflect a little,'' said Gabriel Malagon, a grocery store owner. ``But the criminals who should really get the message can't be reached.''