Colombo: A Sri Lankan state-backed former Tamil Tiger rebel group, accused of abductions and killings, has freed 28 child soldiers, Unicef said on Friday.

The TMVP, made up of fighters who defected from the mainstream Tamil Tigers in 2004, released 11 children in early April.

"We are beginning to see significant progress from the TMVP," said Philippe Duamelle, head of the UN children's agency Unicef in Sri Lanka.

"If the TMVP continues to release at this rate, and refrains from recruiting, they will eventually confirm with their public commitments to release all children," he said.

Unicef estimates more than 5,600 underage fighters have been recruited or re-recruited in Sri Lanka.