Between 1902 and 1910, the town's population rose from 5,000 to 16,000 and grew around administration and tourism, initially in the form of big game hunting. In 1907, Nairobi replaced Mombasa as the capital of the East Africa Protectorate. In 1908, a further outbreak of the plague led to Europeans concluding that the cause was unhygienic conditions in the Indian Bazaar. The government responded by restricting lower class Indians and African natives to specific quarters for residence and trade setting a precedent for racial segregation in the commercial sphere. By the outset of the First World War, Nairobi was well established as a European settler colony through immigration and land alienation. In 1919, Nairobi was declared to be a municipality.