Updated

An international rights group says rebel factions in Syria have recruited teenagers as young as 15 to fight in the country's civil war.

Human Rights Watch says in a new 31-page report released on Monday that rebel groups across the ideological spectrum have used children as fighters, snipers, guards, spies, medical aides and logistical helpers.

The New York-based group says extremist Islamic groups, including the al-Qaida breakaway known as the Islamic State of Iraq and the Levant, have enlisted children by offering free schooling that includes weapons training.

HRW says the Islamic State sometimes sends the children on suicide missions.

Human Rights Watch urged all armed factions in Syria to ban the recruitment and use of children in the conflict.