Five prisoners were killed and many others hurt in a fire at a jail in Kosovo on Saturday. The shooting broke out during a demonstration against what inmates describe as poor living conditions in the prison, to the west of capital Pristina. An investigation was started into the disturbances, the United Nations, which governs Kosovo, said. Already questions are being asked over how this protest -- which started as a simple demonstration -- could spiral so badly out of control. Prisoners barricaded themselves into a building. Hours later, when guards tried to enter to end the disturbance, prisoners set fire to their mattresses. Seventeen other people, including one guard, were treated in hospital.