NICE, France (Reuters) - A bomb has exploded at an air forces barracks in the French Riviera city of Nice, at a building targeted in past attacks linked to separatists from the unruly Mediterranean isle of Corsica, a local prefect says. Local government prefect Pierre Breuil confirmed that the explosion was caused by a bomb. The explosion wounded a woman guarding a school beside the barracks and shattered windows in the area around the building, witnesses on the scene said on Friday. There was no immediate claim of responsibility. Last July, Corsican separatists, who regularly target state buildings on their...