1(in Northern Ireland) 30 January 1972, when British troops shot dead thirteen marchers in Londonderry who were protesting against the government's policy of internment.
2(in Britain) 13 November 1887, when police violently broke up a socialist demonstration in Trafalgar Square, London, against the British government's Irish policy.
3(in Russia) 9 January 1905 (22 January in the New Style calendar), when troops attacked and killed hundreds of unarmed workers who had gathered in St Petersburg to present a petition to the tsar.