A U.S.-based rights group says it has evidence that Syrian forces have captured children as young as age 13 and tortured them during questioning.

Human Rights Watch said Friday in a report that it has documented 12 cases of children being tortured in detention centers. It said many more children may have been treated the same way.

The report said more than 100 people who had been held by Syrian security forces described regular use of torture even against the youngest detainees, beyond the 12 cases profiled.

It said the children reported that they were kept in solitary confinement, beaten, electrocuted, hung from metal handcuffs for prolonged periods, and burned with cigarettes.

Human Rights Watch has called on the U.N. Security Council to demand Syria end all human rights violations and cooperate with human rights investigators and international monitors.