CAIRO (AP) — Forces loyal to a powerful Libyan commander say they are battling former allies, Chadian rebels who have sought refuge in southern Libya as they fight the government in Chad’s capital, N’Djamena. The self-styled Libyan army led by commander Khalifa Hifter said it launched an operation against Chadian mercenaries in the Libyan towns of Tamsah and Tarbo, on the border with Chad. It wasn’t immediately clear what caused the fighting. The clashes, which flared up earlier this week, could further destabilize the wider Sahel region, months after Chadian President Idriss Deby Itno was killed under murky circumstances. The Chadian government blames the rebels for his killing.