The non-governmental organization said the rebel Lord's Resistance Army has abducted at least 100 people since February in Sudan, the Democratic Republic of the Congo and the Central African Republic.

Human Rights Watch said it has obtained "credible information," including documents from foreign and domestic authorities, that indicates abducted boys are forced to become porters or join the fighting force while girls are used as sex slaves.

Joseph Kony, the leader of the LRA, did not show up to sign an April 10 final peace agreement with the Ugandan government. He and other leaders of the rebel group are wanted by the International Criminal Court for alleged war crimes and crimes against humanity.

"Kony and the LRA took advantage of the breathing room given to them and appear to be terrorizing civilians yet again," said Richard Dicker, international justice director at Human Rights Watch. "Concerned governments and U.N. officials cannot sit by while the LRA goes on a criminal rampage, committing heinous abuses against children and other people."