Bangui, Central African Republic—An elderly Muslim met his end under a hail of rocks hurled from a Christian mob during a flare-up of religious hatred here in February. The first stone flew from a 13-year-old Boy Scout.
Children are being drawn into violence in new ways in several parts of Africa—including this country, Nigeria, and Somalia—as religious strife changes the face of conflict. The young have long occupied the front lines of civil wars on the continent, but most of those have ended.
Now, nations here confront a changing, more asymmetrical kind of conflict, featuring Islamic terrorists who use children as martyrs, or Christian lynch mobs who kill Muslims with help from neighborhood teenagers. That puts governments and aid workers up against boys like Anicet N'gueretoum, who aren't quite child soldiers, but also not innocent kids anymore.
For two years, Anicet's homeland, Central African Republic, has been at war, largely between a Muslim rebellion and successive Christian governments. Over the past year, Christian mobs have killed thousands of Muslims, divided the nation and drawn in peacekeepers from France and across Africa.
Much of it is driven by children like him.
"Muslims are animals," Anicet says during an interview at his tin-roof home, posters of rap stars on his bedroom wall.
Young Christians his age have joined mobs that beat Muslims to death. Sometimes their parents disapprove; other times, they join in. Muslim boys, meanwhile, sharpen swords and vow revenge.
In the months since Anicet joined in killing the Muslim man, eight of his teenage friends have helped others hunt down, bludgeon and kill Muslims, according to Anicet, his friends and neighbors.
In between basketball games, they often ask one another if what they have done was wrong, he says. Anicet insists he has no regrets, but worries his actions could spoil his plans to be a senior government official someday.
"Can I become a minister, having committed these acts?" he asks, before turning down an uncle's offer to see a priest.
Across the continent, teenagers are taking roles that defy the easy definition of child soldiering.
In Mali and Somalia, al Qaeda offshoots gave teenagers whips and the task of flogging adults who breach Islamic law.
And in Nigeria, Boko Haram has paid boys and girls to spy on soldiers or burn down schools, the government says.
In April, the world got a glimpse of how the links between war and childhood have deepened there. That month, the Islamic insurgency Boko Haram kidnapped more than 200 teenage girls from a boarding school. It has vowed to use them as slave wives, or to trade them for prisoners. But Nigerian officials note that Boko Haram has also found quasi-military roles for schoolgirls it kidnapped previously, using them to smuggle arms and pass information between Boko Haram camps.
Children were on the front lines in past conflicts in Liberia, Sierra Leone and Democratic Republic of Congo. Those wars have all since ended or in the case of Congo's, eased. Even Joseph Kony's Lord's Resistance Army—notorious for forcing children of East and Central Africa into its ranks—has been contained by years of skirmishes with African troops supported by U.S. military advisers.
One more reason that child soldiers on front lines aren't so common anymore: Child-protection agencies have a powerful set of arguments to bring against warlords who recruit them. The United Nations passed eight resolutions over the past 15 years, promising sanctions, investigations and war-crimes prosecutions against commanders who do. In 2012, a U.N.-sponsored court convicted Liberia's former president, Charles Taylor, of enlisting minors.
Corinne Dufka, senior researcher for Human Rights Watch, recalls traveling to Guinea in the early 2000s to share the news with rebels there that the U.N. was preparing such indictments. Three weeks after Mr. Taylor was indicted in 2003, they issued a directive for all children to be demobilized, she recalled.
"They really paid attention," she says.
Now, Ms. Dufka works on a continent whose front lines are everywhere: Terrorism, some of it by children, strikes city centers and rural villages at random. Religious clashes erupt in neighborhoods Christians and Muslims have shared for centuries.
And the leading rebels here—inspired by al Qaeda—aren't deterred by threats of war-crimes indictments.
Activists often can't meet with the militant groups to persuade them to remove children from their ranks. Instead, in messages delivered through Muslim imams, some try to appeal to their morality: "What I tell them is, 'Would you want your own child on the front line?' " Ms. Dufka says.
But some militants do. In Mali, al Qaeda-allied commanders brought their own children to shooting practice in Timbuktu, recalled three guards and gardeners at one base. In Somalia, fathers haven't only recruited their sons—but also filmed their own children, as young as 10, dying as suicide bombers, Human Rights Watch says. Boko Haram leaders have raised their sons as martyrs, too, says Fatima Akilu, director of behavioral analysis in the office of Nigeria's national-security adviser.
The Christian side of the religious divide presents its own problems. In Central African Republic, Christian mobs set off to kill Muslims found at random. Many here want to cleanse the country of Muslims, a minority they blame for fueling a civil war.
Children here aren't just joining those mobs but leading them. This was also the case when a bomb went off in Jos, Nigeria, in May: Furious Christian teenagers who assumed Islamic militants were behind the blast erected a checkpoint on the road and beat a Muslim man, residents said.
"They are under the control of nobody," said Souleymane Diabate, the United Nations Children's Fund's country representative to Central African Republic. "The lack of a chain of command, it poses a problem."
For a time, Anicet, now 14, looked as if he might reach adulthood in peace. Though a war of increasingly religious tone was sweeping his country, in 2012 and 2013, he was at school, in a village. The violence never reached him there. None of his loved ones were killed or assaulted.
Then his school closed and he moved back late last year to Bangui, a sleepy, riverside capital. His parents separated shortly after he arrived: His father is no longer around.
On Saturdays, Anicet attended Boy Scout meetings. He also played soccer and developed a crush on a bashful girl in the neighborhood, named Noella.
Meanwhile, he found work pushing a cart through the streets, helping neighbors shift their belongings to safer parts of town. Along the way, he heard stories about Muslims killing Christians, or raping young girls.
In February, he left his house after a nap to play soccer. On his way, he said, he spotted an old Muslim man encircled by a furious mob.
Drawing from a place of anger he can't fully explain, he hurled a rock at the Muslim man's head. Then another. The second toppled the man to the ground, and with that, the crowd began stomping away until another young man lifted a massive boulder and dropped it on the Muslim's head.
As the crowd faded, Anicet stole the dead man's belt. It is crackled, black, of fake leather.
Now he keeps it in his bedroom, alongside the other souvenirs he has since looted from Muslim homes, including from a second Muslim man he says he helped his friends kill since then. They include bank notes from Egypt and Saudi Arabia and a book titled: "To Know Islam." The cover says it is to be distributed at no charge—to spread the faith.
"He's a thief," said his mother, Noella Yombimet. "He's with bad people.…He doesn't listen to me."
But his friends feel differently. Like them, he packs a homemade sword in his trousers. He joins them at a video lounge many mornings, where they watch martial-arts films and scream at the television.
"We are proud of him," said a 19-year-old who calls himself "FBI" and nicknamed Anicet "CIA." "What he did was good."
—Frederic Lafargue contributed to this article.