In Canada opposition to conscription and involvement in the war centered on French Canadian nationalists led by Henri Bourassa. Following the 1917 elections, the government implemented the Military Service Act 1917 that came into effect in 1918, which sparked a weekend of rioting in Quebec City between March 28 and April 1, 1918. Invoking the War Measures Act of 1914, the federal government sent troops to restore order in the city, which opened fire on a demonstration on April 1.