Ciudad Juarez, Mexico (AFP)— Mexico sought answers yesterday after five children aged 11 to 15 stoned, stabbed and buried a six-year-old boy, a shocking case that raised questions about the influence of drug violence on kids.

The boy was found in a shallow grave by a stream on Saturday, two days after he was last seen with a group of children on the outskirts of the Chihuahua state capital, the regional prosecutor’s office said.

Cristopher Raymundo Marquez Mora was found after investigators interrogated the children, who include two 13-year-old girls, one 11-year-old boy and two 15-year-old boys.

The five were detained as “probable culprits in an act that reflects a problem of social decay”, the prosecutor’s office said in a statement.

The victim disappeared late Thursday and his mother reported his disappearance the next morning, sparking a search.

The boy and the other children are neighbours who knew each other.

“They were playing, they tied him up and they put a stick on his neck that semi-asphyxiated him,” the statement said.

“When the boy fell to the ground, they hurled rocks at him, they stuck a knife in his back and once dead, they dragged him where they deposited the body, in a shallow dig,” it said.

“They covered the body with dirt and put plants and a dead animal on the surface” in a bid to hide him, the statement said.

The two 15-year-old boys could be jailed if found guilty but the three other minors face “other types of sanctions,” prosecutors said.

The murder took place in a state that has endured some of the worst bloodshed in Mexico’s drug war, with thousands of people killed in turf wars between cartels.

Chihuahua, which borders Texas, is home to Ciudad Juarez, which was once considered the world’s murder capital outside a warzone as the Juarez and Sinaloa drug cartels fought for the territory.

The city’s murder rate has dramatically dropped in the past four years but the state continues to witness murders, torture, kidnappings and extortion.

The five children accused of murder “are victims of an environment of extreme violence”, said Juan Martin Perez, executive director of the Children’s Rights Network, a non-governmental organisation.

“There’s a strong presence and culture of organised crime and a lack of culture of rule of law,” he said. “The children reflect what they experience every day.”

Carlos Ochoa, a forensic and criminology expert, said cases like the six-year-old’s killing mark “the start of a generation of psychopaths, who are getting younger”.

Ochoa recalled the 2013 case of a 17-year-old girl from Chihuahua who poisoned and burned her adoptive parents.

The mother of Cristopher, Concepcion Mora, angrily rejected the explanation that the children killed her son during a game.

“It’s illogical for it to be a game,” she said Sunday as relatives and neighbours joined her in a protest. “They should pay for my son’s life.”

One of the boy’s aunts warned: “We want vengeance. If they don’t give us justice, we will take revenge.”