A bus accident in Warsaw on Thursday has left 33 people injured, eight seriously, local media reported, according to DPA. The accident occurred as the bus, a part of the city mass transportation system, was crashed into by another vehicle as the bus attempted to change lanes. The bus broke through a barrier and crashed into a tree before overturning. Emergency doctors set up a tent near the accident to handle the injuries which included numerous broken bones. Traffic in one of the most important east-west routes of Warsaw was blocked for hours.