More than 100 firefighters were battling a fire on Wednesday at the Mandarin Oriental Hotel in London's upscale Knightsbridge neighborhood. There were no immediate reports of injuries. The fire is on the roof of the 5-star hotel, and the London Fire Brigade said 120 firefighters and 20 fire engines were working to extinguish the blaze. Video posted on Twitter by the London Fire Brigade showed heavy, black smoke rising into the air from the hotel. The property of 12 floors overlooks London's famed Hyde Park.