THE Constitutional Court has ruled that minimum sentences infringe on the rights of children aged 16 and 17.

Handing down the judgment yesterday, Judge Edwin Cameron said the approach required by the minimum sentencing "unjustifiably infringes the protection the Bill of Rights afforded to all children under 18".

In December 2007, the Criminal Law Amendment Act came into effect and made minimum sentences for serious crimes applicable to offenders aged 16 and 17.

Previously, these children were largely exempted from the minimum sentencing provisions that Parliament enacted for serious offences in 1997.

The Centre for Child Law at the University of Pretoria successfully challenged the statute in the North Gauteng high court.

The respondents were the ministers of justice and constitutional development, and of correctional services and the Legal Aid Board.

Cameron said the courts should use other means, including long and heavier sentences, to deal with child offenders.

"The Constitution itself recognises children's greater vulnerability.

"The Constitution requires an individuated judicial response to sentencing for children that focuses on the particular child being sentenced."

He said minimum sentencing limited sentencing officers from using their discretion as it prescribed incarceration.

But the ruling excluded children already sentenced.

Centre for Child Law spokesperson Carina du Toit welcomed the ruling. She said they would appeal the sentencing of child offenders already in prison.