The move came ahead of a crucial United Nations meeting next month on the human rights situation on the island.
The committee will "inquire into allegations of abduction and recruitment of children for use in armed conflict with immediate effect," Human Rights Minister Mahinda Samarasinghe said in a statement here.
The Sri Lankan government has come under severe criticism from local and international rights groups for allegedly colluding with the breakaway Tamil rebel faction known as the Karuna group.
Last year, the UN accused Sri Lankan government forces and police of rounding up children in the embattled east of the island to be recruited by the Karuna group, a charge vehemently denied by authorities at the time.
The New York-based Human Rights Watch has said it saw children under the age of 17, some armed with assault rifles, guarding offices of the Karuna group in the eastern district of Batticaloa while Sri Lankan troops passed by.
The rights group said the government