Two Syrian nationals were detained on charges of killing an 8-year-old Syrian boy they kidnapped for ransom in southern Turkey.Sorach Muslem was found bound, gagged and strangled in an empty house in the city of Mersin on Thursday, two days after suspects abducted him and asked for a ransom from his family.Police said two men, hailing from Kobani, the Syrian hometown of the boy, were preparing to return to Syria when they were captured on Friday.