As their mission stretches into a fifth year, however, U.S. troops have turned to some unsavory partners to help find Kony’s trail. Working from a new bush camp in the Central African Republic, U.S. forces have begun working closely with Muslim rebels — known as Seleka — who toppled the central government two years ago and triggered a still-raging sectarian war with a campaign of mass rapes and executions.

The Pentagon had not previously disclosed that it is cooperating with Seleka and obtaining intelligence from the rebels. The arrangement has made some U.S. troops uncomfortable.

The Seleka rebels “are playing us,” said one military official who spoke on the condition of anonymity because he wasn’t authorized to talk with reporters. The official described Seleka as a “mafia” that is trying to curry favor with the Americans even as the rebels extort local villagers and engage in illicit trade with Kony’s fugitive fighters.