GULU, Uganda – As she prepared her bed for the night, the little girl’s wide, frightened eyes shone through the darkness. Simple Aber, 12, huddled in a ragged strip of cloth, lying inches from a fetid heap of rubbish. “My mother told me, ‘You must leave the village and sleep in the town because of the war. If you stay, you will be taken,’ ” she said.

Simple is among 20,000 children, some as young as 6, who stream into the town of Gulu in Uganda every night. This twilight procession of tiny, barefoot figures lives in fear of abduction.

For northern Uganda is the hunting ground of the Lord’s Resistance Army, LRA, Africa’s most brutal rebel group, led by a self-styled prophet called Joseph Kony.

Since the onset of his campaign 18 years ago, the LRA has kidnapped 20,000 children, brainwashing and enslaving them for use as soldiers and sexual playthings. More than 10,000 have disappeared in the last two years.

Mr. Kony targets children, devoting his messianic energies towards the abduction, indoctrination, and often murder of as many as possible.

The catastrophe inflicted is almost without parallel. At least 1.6 million people – virtually the entire rural population – have fled their villages for squalid refugee camps. The number of refugees has trebled since 2002 and exceeds the 1.2 million in Sudan’s war torn Darfur.

Simple sleeps on concrete outside Gulu district hospital – six miles from her village of Eriaga in the rebel-infested bush. Scores of children huddle around her.

They are trying to avoid the fate of Bosco Ayella, 15. The LRA kidnapped him when he was 12 and the terrified boy was dragged before a rebel commander. He told Bosco and four other captives that they were now LRA fighters.

“The rebels had five boys who were captured,” said Bosco. “The commander ordered us to kill them. I said, ‘We can’t kill them.’ The commander said, ‘If you won’t kill them, we will kill you.’ The rebels picked up clubs and hoes. We asked for mercy and said we would kill those boys.”

Bosco and the other captives were handed clubs and ordered to “crush their heads.”

“We began hitting them. They were crying for mercy,” said Bosco. “Their blood was going everywhere. They were crying out but no one was listening. We beat them to death. From that time on, I felt I could not eat meat. I started having nightmares.”

Bosco spent three years with the LRA. He soon fell under Mr. Kony’s spell and even today the rebel’s supposed supernatural powers exert a hold. “Whenever Kony predicts something, it comes true. When he gives an order, if you fail to do it, you die immediately.”

But Bosco was determined to escape. The LRA operated from bases in neighboring Sudan. Bosco managed to slip away and surrender to Sudanese soldiers. He was repatriated last month and is now at the Children of War Rehabilitation Centre in Gulu.

Here,530 children who have escaped the LRA are given counseling and medical care before being reunited with their families.

Florence Lakot, 24, escaped last month with her daughter, Senasca, 6. Her child was born in the bush, two years after Ms. Lakot’s abduction at the age of 16.

Like most of the LRA’s female captives, she was given to a rebel commander as a “wife” – his seventh. “When I was first given to him, he said, ‘You despise me. You must be beaten.’ He got four tough boys to beat me with sticks until I was unconscious. He did this twice. He said this was to beat the civilian out of me and make me a soldier,” said Ms. Lakot.

After eight years with the LRA, she managed to surrender alongside some rebel commanders. All LRA fighters, including Mr. Kony, are eligible for an amnesty if they turn themselves in.

The rebellion grew from the grievances of the Acholi people, who believed that President Museveni’s government was discriminating against them.

Mr. Kony merged this resentment with religious fanaticism. But he never offered coherent demands, pledging only to rule according to the Ten Commandments. Today, his rebellion has no aim except rebellion itself. No one in Gulu doubts that if Mr. Kony surrendered, the war would end.

The clinic inside Gulu’s rehabilitation center displays dozens of photographs of children mutilated by rebels – infants without noses, lips, hands, or feet.

Tabitha Ochen, the nurse, has treated many of them. Asked whether she could forgive Mr. Kony, she replied: “Yes, I have already forgiven him.”