French troops that have intervened in the fighting are very popular in Mali, but the militants, who are not, have taken steps to improve their image among the young, McClatchy Newspapers reported Tuesday.
Witnesses say the militants invite children to join them for tea and give them candy. They tell the youths they are free to walk around town.
They also give the boys money and ask for information about people in the village to learn who are government soldiers or officials, who are then executed.
The gestures to the youth have had results, the McClatchy report said.
Fousseni Traore, a 19-year-old resident in the town of Diabaly, said he saw children as young as 13 fighting with the militants.
"There were more than a hundred of them my age," said Saidou Berte, 14.
Hundreds of children have been trained by the militants since April 2012, when the rebels took over northern Mali, says Human Rights Watch. Witnesses say they have seen fighters as young as 12 in the rebels' ranks.