BAMAKO, Mali (AP) — A witness and a combatant affiliated with radical Islamists in northern Mali say the al-Qaida-linked group has enlisted new fighters from a tribal militia to strengthen its grip on the region.

A resident of Douentza town told The Associated Press on Sunday that some 400 combatants of the government-backed Gandakoy militia appear to have broken ranks and joined the Islamists, bolstering the radicals’ edge over ethnic Tuareg rebels in the area. The witness declined to be named for fear of reprisals by the Islamists of the Ansar Dine group.

One of the group’s Timbuktu-based fighters, Oumar Ould Hamaha, confirmed the resident’s observation, saying the Gandakoy militants in in Douentza are "100 percent with Ansar Dine."

The group’s spokesman, Sanda Abou Mohamed, also confirmed that the Gandakoy "who respect our principles" arrived in Douentza, some 250 kilometers (150 miles) south of Timbuktu.