Libya’s Missing Persons Authority announced Sunday the discovery of 42 bodies buried in a mass grave in the central coastal city of Sirte, a former stronghold of the ousted Islamic State group. In a statement, the authority’s spokesperson said the 42 bodies had been exhumed from a school site in the city following a “tip off” from an investigation conducted with captured Islamic State fighters. Sirte, the birthplace of former longtime dictator Muammar Gadhafi, fell under Islamic State control between 2015 and 2016, as the extremist group sought to profit from the chaos that engulfed the oil-ri…