Children are being used as sniper targets and human shields in the Syria war, the United Nations says, in a report that adds Mali to its child soldier list of shame.
UN leader Ban Ki-moon says in the report the 26-month-old war in Syria is taking an "unacceptable and unbearable" toll on children, with thousands among the death toll.
The office of UN special representative on children in conflict, Leila Zerrougui said it had received "verified reports that Syrian children are killed or injured in indiscriminate bombings, shot by snipers, used as human shields or victims of terror tactics".
Zerrougui presented the report, which says boys as young as 10 are used by armed groups to work as combatants and porters.
It says there are a growing number of reports of the Free Syrian Army, the main rebel group, recruiting children, mostly between 15 and 17.
Sexual violence has been used by President Bashar al-Assad's forces against boys to obtain information or confessions, the special representative said.
Child detainees as young as 14 are tortured like adults "including electric shock, beatings, stress positions and threats and acts of sexual torture", the report says. Thousands of children "have seen family members killed or injured".
"Everyone involved in the conflict needs to take urgent measures to protect children," Zerrougui said.
"Allowing access for lifesaving humanitarian assistance is essential. We cannot allow innocent children to continue to die because they can't see a doctor, or because they can't fulfill their basic needs."
Mali, where Islamist groups took over the north of the country until a French-led intervention in January, is the only new country added to the UN blacklist released each year.
Tuareg rebels, al-Qaeda Islamists and pro-government militias used hundreds of child soldiers in Mali, Zerrougui said.
Children make up more than half of Mali's population of 15.8 million and many have been abducted for armed groups and girls forced to become the wives of combatants.
"Sexual violence against girls by armed groups was reported to be widespread and systematic in northern Mali," says the report, which highlights hundreds of cases of rape, gang rape, sexual slavery and forced marriage since the uprising in March last year.
Chad's national army is on the UN list but is also being considered for the UN peacekeeping force scheduled to deploy in Mali next month. But Zerrougui said Chad's government had made a "very strong commitment" to end the use of child soldiers.
Widespread use of child combatants and sexual violence has also been reported in Central African Republic.
Nine government armies and 46 armed groups - ranging from national armies in Afghanistan and Somalia to rebel groups in Myanmar and the Philippines - are on the UN list for using children as soldiers or torturing and raping children.
Zerrougui said action plans to end the use of child soldiers had been launched with government forces and armed groups in Myanmar, Somalia, Democratic Republic of Congo and South Sudan.
Thousands of children also had been released by armed groups in 2012.
Nepal and Sri Lanka have been taken off the UN list.