Eleven people were injured on Friday afternoon in Vienna, when an open-topped tourist bus rammed a streetcar in the Austrian capital, according to DPA. The bus driver had overlooked a tram in Vienna's city centre when he was about to execute a turn and rammed it, a police spokesman said. A German tourist group consisting of nine was injured, as well as the drivers of both vehicles. The two drivers and one tourist were hospitalized with severe injuries, the remaining tourists suffered slight injuries. The cause of the accident is still unclear, authorities said.