The rebel Liberation Tigers of Tamil Eelam (LTTE) said the 22 youngsters had joined the movement by giving false information about their ages, and most of them were handed over to their parents Friday.
Two others were sent to an organisation to provide them with vocational training, the LTTE said in a statement.
Earlier this year, the LTTE clashed with the United Nations Children's Fund over child recruitment and disputed a list of 1,387 children said to be among rebel ranks.
The rebels said more than 800 of them were over 18 years old.
The LTTE said some children joined their movement out of poverty and the lack of any livelihood in the embattled north of the country, while others lied about their actual age. Some children also did not have birth certificates.
UNICEF documented 3,516 news cases of under-aged recruitment by the LTTE between February 2002, when a cease-fire was reached with the government, and October 2004.
The LTTE has waged a battle for a separate Tamil homeland in the north of the island nation that has claimed more than 60,000 lives since 1972.
Violence on the island has escalated since December 2005, with nearly 3,300 people killed despite the cease-fire.

Copyright AFP (Agence France-Presse), 2006