(ANSA-AFP) - FRANKFURT, 23 MAG - Two trams collided head-on in the German city of Duesseldorf on Saturday, injuring over 50 people, including many who needed hospital treatment, the fire service said. The accident happened at around 11:30 am (0930 GMT) at a busy intersection of the western city, and emergency services were quickly deployed to the scene. Twenty-eight of the injured were taken to hospital, while another 28 were more lightly injured and received treatment at the scene, said a fire service statement. The cause of the accident was not immediately clear and police have launched an investigation. (ANSA-AFP).