pbr An explosion at the largest coke manufacturing facility in the US has injured at least 15 people and forced a partial suspension of the US Steel operations in Clairton, Pennsylvania.br ppbr There was a fire in No. 2 B battery and apparently there was flammable gas that ignited and exploded, Robert Szymanski, director of the US Occupational Safety and Health Administration office in Pittsburgh, told the Pittsburgh Post-Gazette.br ppbr The injured were taken to area hospitals, University of Pittsburgh Medical Center spokeswoman Gloria Kreps told reporters.br ppbr A spokeswoman for US Steel confirmed there was an explosion and fire that resulted in injuries at the Clairton plant. But she declined to give numbers or confirm any disruption of operations, saying only that the company would assess "the extent of repairs and impact on operations" later.br ppbr The Clairton plant operates 12 coke oven batteries and producing approximately 4.7 million tons of coke annually. The plant serves the commercial coke market plus US Steel's steelmaking facilities.br ppbr Coke is made from coking coal and is used to make steel along with iron ore.