Myanmar's army has freed 68 children and young people from military service, the United Nations said Wednesday, calling for a "mass release" of child soldiers in the formerly junta-run nation.

The release is the biggest such move since the UN signed an agreement on the issue in June 2012 with Myanmar's reformist regime and "tatmadaw" army, which for years recruited children to bolster its ranks.

In a little over a year, 176 children and young people have been discharged from the military, which has decreased -- but not yet stopped -- the recruitment of children to the armed forces.

"The time has come for the mass release of all children from the Myanmar armed forces," Shalini Bahuguna, deputy representative for UNICEF in Myanmar, said in a statement.

There are no verifiable figures on how many children are currently serving in Myanmar's huge military, which has faced a slew of accusations of rights abuses including the forced recruitment of children and other civilians to work as porters or even human mine detectors.

Ending rights violations is a key demand of the international community, which has embraced reforms in Myanmar since the end of outright junta rule in 2011.

Myanmar released 42 children in September last year, 24 in February and a further 42 in July. All of those freed were recruited as children, but some have since become adults.

"I have always said the military is not a place for a child to grow up. We are very happy for the children and young people being discharged today," said Ashok Nigam, the UN's resident coordinator in Myanmar.

The UN also urged ethnic rebels to end their recruitment of children, listing seven non-state armed groups that are also accused of co-opting under-age personnel.

A quasi-civilian regime led by former general Thein Sein has been praised by foreign governments for reforms including welcoming democracy champion Aung San Suu Kyi and her opposition political party into parliament.

His government has also reached tentative peace deals with major armed ethnic minority rebel groups in the country, which has been wracked by civil wars since independence from British colonial rule in 1948.