UNITED NATIONS - Syrian troops and rebels are recruiting children to fight in the country's civil war and some have been tortured by government forces for having links to the opposition, UN chief Ban Ki-moon said in a report on Wednesday.The report issued after Ban's special envoy for children and armed conflict, Leila Zerrougui, visited Syria in December said thousands of children have been killed in the violence, "while thousands more have seen family members killed or injured."The report said there had been a spike in grave violations against children by both government troops and armed groups in the Democratic Republic of Congo, amid a year-long insurgency by M23 rebels. U.N. experts accused Rwanda supporting M23 last year, but Rwanda denies the accusation."M23 was responsible for systematic recruitment and use of children," the report said. "A total of 65 boys between 13 and 17 years of age, including 25 who claimed to be Rwandan, escaped or surrendered from M23 between April and December.""A total of 21 of those boys ... said that they had been recruited on Rwandan territory," it said. "While initially used as porters, most ended up on the battlefield as combatants or escorts of commanders. Testimonies from former M23 combatants suggested that hundreds of children remained in M23."The report also said children are recruited, killed, maimed or raped by government forces and armed groups in Afghanistan, Chad, the Democratic Republic of Congo, Somalia, Sudan, South Sudan and Yemen, as well as by armed groups in Mali, Colombia, the Philippines, Myanmar, Iraq and the Central African Republic.The United Nations considers anyone aged under 18 to be a child.Ban said that in Syria, torture and ill-treatment of children accused of associating with opposition forces was a worrying trend."There were a number of accounts of sexual violence against boys to obtain information or a confession by the state forces, largely but not exclusively by members of the state intelligence services and the Syrian armed forces," the report said."Child detainees, largely boys and as young as 14 years old, suffered similar or identical methods of tortures as adults, including electric shock, beatings, stress positions and threats and acts of sexual torture," it said.Armed opposition groups, including the Free Syrian Army, were also accused of using children, generally aged 15 to 17 years old, both in combat and in support roles, such as ferrying food and water and loading cartridges, the report said."From accounts received, child association with the Free Syrian Army is often linked to an older relative facilitating recruitment or in instances in which the child has lost all members of his or her family," it said.Ban said that the Syrian government and the National Coalition of Syrian Revolutionary and Opposition Forces had assured Zerrougui that they were committed to working with the United Nations to stop the abuse of children's rights.CHAD WORKING TO STAMP OUT CHILD SOLDIERSThe report said that in Chad, while progress had been made and the army had a policy of not recruiting children, there were 34 verified cases child recruitment by the army in 2012."All 34 children appeared to have been enlisted in the context of a recruitment drive between February and March 2012, during which the army gained 8,000 new recruits," it said.Chadian troops played a key role in helping French forces during a military offensive in January to drive out Islamist fighters who seized two-thirds of Mali.Diplomats have said Chad is working with the United Nations to stamp out child soldier recruitment so the country can potentially be part of a peacekeeping force in Mali, which is set to assume authority next month.