SANAA, Yemen (AP) — Yemeni officials say fresh fighting between Hawthi rebels and ultra-conservative Salafi tribesmen has left at least 26 militants dead.

They say 17 were killed Wednesday in the mountainous Arhab region north of the capital, Sanaa, and nine others elsewhere in the nearby Amran province. The officials, who spoke on condition of anonymity because they were not authorized to speak to the press, say that many of the fighters are boys younger than 18.

Security and tribal officials in Arhab say that the Salafi tribesmen are trying to retake control of the mountain range from the Hawthis. Fighting broke out Monday after a two-weeklong truce fell apart, killing 21. The truce had put an end to weeks of violence that had killed hundreds from both groups.