A shortage of potatoes, the well-known main Dutch food, caused a bloody riot in Amsterdam towards the end of June 1917. It was called the "Aardappeloproer" (Potato Revolt), and it lasted a week. Everywhere in the city plunderers tried to obtain food. Potatoes were scarce and very expensive as a result of the First World War. The police and the military fired at the demonstrators. Only after seven days was peace restored in the city, and the results of the riot were totaled: ten people killed and more than a hundred wounded.