A feared militia along Sri Lanka's volatile eastern coast has abducted hundreds of men and boys - some as young as 12 - and is training them for combat in camps operated with the government's consent, witnesses and officials said.

The so-called Karuna Group takes its forced recruits to rudimentary thatched-roofed bases near army compounds where they are used as labourers or taught to use weapons, witnesses, family members and aid workers told The Associated Press in recent interviews.

Named for its commander, who goes by the nom de guerre "Karuna," the paramilitaries have added a new factor to Sri Lanka's civil war, which began in 1983 and has savaged the nation. Their existence also complicates efforts by foreign mediators to revive peace negotiations.

By allowing Karuna's forces to operate, the government has gained an ally against a common enemy, said Robert Karniol, Asia Pacific bureau chief for Jane's Defense Weekly.

"The Tamil Tigers are a serious threat to the government and anything that weakens or distracts from that is advantageous to Colombo," Karniol said.

The Karuna faction split from the Liberation Tigers of Tamil Eelam in 2004, with Karuna saying the larger group didn't defend the interests of the country's eastern Tamils. The faction has since built up a strong military presence in the island's east.

It is demanding a role in peace talks with the government and says there can be no solution without them.

Hundreds of Karuna fighters are terrorizing the district of Batticaloa, the scene of a rash of abductions that began in March, residents said.

The total number of disappearances is unclear because so many go unreported, but officials from several aid organizations estimate at least 300 people have been taken by Karuna's men this year.

"It has definitely been hundreds and it might not be all of them," said Bjorn Kjelsaas of the Sri Lanka Monitoring Mission, established to oversee the 2002 cease-fire.

The government, for its part, denies helping the Karuna faction.

"We don't know about his (Karuna's) whereabouts. We have been right throughout denying that we are involved with them," the government's national security spokesman, Keheliya Rambukwella, said.

But the two forces clearly work together, many people say. Karuna faction troops, mostly dressed in civilian clothing, work alongside police and army officials at roadblocks, according to a high-ranking local official and aid workers. Because of the violence in the area - unexplained killings happen nearly every day, as various factions battle for supremacy - only a handful of people were willing to use their names.

A leader of the faction's political wing, E. Prethip, told The Associated Press that the group's members are "volunteers."

He blamed the Tamil Tigers for committing atrocities in Karuna's name, and said members were armed only in self defence.

"They carry out ambushes, loot houses, kill civilians. They kidnap the children and they say it was done by Karuna," Prethip said in his office, where children served visitors drinks.

"Our military does not cooperate with the Sri Lankan army, but we're not enemies either," he said, sitting in front of a bookcase filled with children's books and a recent copy of "Eye Spy" intelligence magazine.

The disappearances have become so common that almost every family around Batticaloa has lost a son, or knows someone who has, residents said. A teacher said his 10th grade high school class had almost no boys left.

Scores of underage boys - sometimes dozens at once - have been rounded up at their homes, Hindu temples, schools or by the side of the road and spirited away in white vans, according to witnesses and confidential case files presented to Sri Lankan prosecutors and the Ministry for Human Rights and obtained by The Associated Press.

In the most recent known case, two dozen youngsters were taken from a single village on September 24, said a human rights activist who spoke on condition of anonymity because she feared for her life.

In a desperate attempt to protect their children, many families have sent their sons to safe houses, a local resident said.

Some Karuna Group recruits receive wages, normally around 6,000 rupees a month, with two thirds generally going to the family. Relatives are sometimes allowed to visit the camps, often in exchange for not going to authorities, aid workers said.

"The communities seem to know who is taking their children and they live in fear and are in need of protection," said Marcel Smits, head of the aid group Nonviolent Peaceforce Sri Lanka.

Parents who had visited said their children were receiving military training to fight the Tigers, Smits said.

One couple, whose names were withheld to protect them, told The Associated Press their 16-year-old son was taken by a neighbour eight months ago and has not been seen again.

The parents are too scared to go to the police, choosing to suffer silently while protecting the three boys they still have.

"We didn't try to go after him and don't know where he is," said the father, as his wife huddled in a corner, staring blankly into the glow of an oil lamp. "We just want to have an ordinary life."