An international human rights group has called on the UN Security Council to impose sanctions on Sri Lanka's Tamil Tiger rebels for using child soldiers.
Children have long been caught up in Sri Lanka's conflict
A Human Rights Watch (HRW) report has also accused the government of ignoring child recruitment by an allied paramilitary force.
HRW made its allegations as UN experts met to discuss the use of underage soldiers in the Sri Lankan war.
A UN envoy is visiting the island nation to assess the conflict.
"The Security Council should punish their brazen violations with concrete action," HRW child rights advocate Jo Becker said.
Correspondents say that international rights groups have for many years criticised the Tamil Tigers and other armed groups in Sri Lanka for forcibly recruiting children.
Heavy fighting has been going on in the north and east
The rebels have consistently promised to stop using them.
HRW says that while there is evidence that the recruitment of children has dropped significantly, the problem continues.
According to the UN children's agency, Unicef, there were at least 196 children in the guerrilla force at the end of January.
HRW have also accused the breakaway Tamil Tiger faction led by Col Karuna of recruiting child soldiers.
Col Karuna - who is currently serving a nine month prison sentence in Britain for identity fraud - is now allied with the government.
Ms Becker said that the Tigers and Col Karuna "continue to use children to fight their battles in clear violation of international law and Security Council resolutions".
The Sri Lankan government has sent a three-member team to New York to present its case to UN experts meeting to discuss the problem of child soldiers in Sri Lanka.
"Our position, as far as the government is concerned, has always been a zero tolerance policy on child recruitment," said , said Human Rights Minister Mahinda Samarasinghe.
Rebel spokesmen were not available for comment.
But in the past they have insisted that they are abiding by pledges to stop using child soldiers.
The Tigers have been fighting for an independent state in the north and east since 1983. More than 70,000 people have been killed since then.
They say that ethnic minority Tamils have been marginalised for decades by governments dominated by the Sinhalese majority.