GUNMEN burned a Catholic priest to death and shot and injured his colleague in northwest Nigeria, police said, the latest violence raising concerns about security ahead of an election next month. Nigerians will vote for a new president on February 25 but kidnappings for ransom and killings by armed gangs in the north have led to fears that polls may not be held in some areas. The motive for the latest attack was not immediately clear but gunmen have previously targeted priests in the largely Muslim north. Wasiu Abiodun, police spokesperson for Niger state, said in a statement that armed…