* U.N. Security Council envoys visiting Congo and Rwanda
* Rwanda denies backing M23 rebellion in Congo's east
* U.S. blocks military aid to Rwanda over child soldiers
A third of child soldiers who have escaped from Congolese rebel group M23 were lured from neighbouring Rwanda with promises of cash, jobs and education, the United Nations said on Saturday.
Some M23 child soldiers received training from the Rwandan Defence Force for up to two weeks before being handed over to the rebel group, with some of the children believing mistakenly that they were joining the Rwandan army, the chief of child protection at the U.N. peacekeeping mission in the country said.
U.N. experts have repeatedly accused Rwanda of backing the 18-month-long M23 insurgency in eastern Congo, a charge the Rwandan government has fiercely rejected. The roots of the Tutsi-dominated rebellion lie in the 1994 genocide in Rwanda, where Hutu troops killed 800,000 Tutsis and moderate Hutus.
Since the rebellion began, the U.N. peacekeeping mission in Congo - known as MONUSCO - has interviewed 117 boys who were recruited by M23 and found 37 of them were Rwandan.
There are still a couple of hundred children among the M23 ranks, MONUSCO's chief of child protection Dee Brillenburg Wurth told reporters in Kinshasa during a visit by U.N. Security Council ambassadors to the Democratic Republic of Congo.
She said four of the boys said they received military training by the Rwandan Defence Force in Rwanda at camps in Bigogwe, Ruhengeri-Nyarubanda and at the former university campus in Mundende before they were handed over to M23.
"(They were given) very, very sophisticated training, very serious training, some of them by Rwandans. They said some of the trainers had Rwandan uniforms on," said Brillenburg Wurth.
"Some of (the children) thought they were being recruited in the Rwandan Defence Force and they were trained in Rwanda and then they found themselves ... in Congo," she said, adding that cash rewards, education and job opportunities were also used to recruit groups of children in Rwanda.
Brillenburg Wurth said the ages of the child soldiers ranged from 11 to 17 and most were aged 15, 16 or 17. She said some children told how they had been recruited by a football coach and a police officer, who were earning $5 per child.
The United States, which has called on Rwanda to drop its support for the M23 rebels, stepped up its pressure on Kigali last week by moving to block military aid over the recruitment of M23 child soldiers in its territory.
DISOBEY AND DIE
The former M23 child soldiers said they were regularly posted on the frontline and saw many other children killed.
"Within the group there is an extremely tough hierarchy and discipline. People who didn't obey orders were just killed. One child told how he had to kill two adults who had done some infraction," Brillenburg Wurth said.
Among several M23 officers accused by the former child solders of recruiting, torturing and killing children are Innocent Zimurinda and Baudouin Ngaruye, who are both subject to a U.N. travel ban and asset freeze.
The United Nations has said Zimurinda and Ngaruye fled to Rwanda in March with fellow officers Jean-Marie Runiga and Eric Badege, also under U.N. sanctions, after M23 suffered a violent internal split. They escaped with warlord Bosco Ntaganda who was defeated by rival M23 commander Sultani Makenga.
In July the Congolese government issued international arrest warrants and extradition requests to the Rwandan government for the four men on charges of commission of war crimes and crimes against humanity, the United Nations said.
The U.N. Security Council delegation, which includes U.S. Ambassador Samantha Power and British Ambassador Mark Lyall Grant, is due to travel to Rwanda on Sunday, where they plan to discuss how former M23 combatants who fled to Rwanda can be dealt with in accordance with relevant international law.
The United States last week partially blocked military aid to Congo over the issue of child soldiers.
Brillenburg Wurth expressed surprise at Washington's decision regarding the Democratic Republic of Congo, which last year signed an action plan with the United Nations to stop and prevent recruitment of child soldiers.
"There have been huge results... They don't recruit children any more. There's been zero tolerance," she said.