Four people have been injured after an explosion caused a fire at an oil refinery in southern Germany, police said on Friday. The incident in Neustadt an der Donau, north of Munich, was reported at around midnight (2300 GMT Thursday), with a large contingent of fire brigades deployed to the scene. According to the police, the cause of the explosion and fire initially remained unclear, as did the extent of the damage. The Bayernoil refinery company said the fire broke out in a processing plant. T