riots (including several fatalities) during this period. Following riots in support of Egypt defending itself against the tripartite invasion during 1956 Suez Crisis, the British decided to put an end to the NUC challenge to their presence in Bahrain. The NUC and its offshoots were declared illegal. Its leaders were arrested, tried and imprisoned. Some fled the country while others were forcibly deported. Strikes and riots continued during the 1960s, now under the leadership of underground cells of the NUC, namely the communist National Liberation Front and the Popular Front for the Liberation of Bahrain, the Bahraini section of the Arab Nationalist Movement. In March 1965, an uprising broke out, called the March Intifada, against the British presence in Bahrain. The spark of the riots was the laying off of hundreds of Bahraini workers at the Bahrain Petroleum Company. Several people died in the sometimes violent clashes between protesters and police. Independent Bahrain After World War II, Bahrain became the centre for British administration of the lower Persian Gulf. In 1968, when the British Government announced its decision to end the treaty relationships with the Persian Gulf sheikdoms, Bahrain joined with Qatar and the seven Trucial States (which now form the United Arab Emirates) under British protection in an effort to form a union of Arab emirates. By mid-1971, however, the nine sheikhdoms still had not agreed on the terms of union. Accordingly, Bahrain sought independence as a separate entity. In 1969, both the British and Iranian governments agreed to approach the United Nations Secretariat to resolve the dispute of Bahrain's sovereignty. In early 1970, the Iranian government asked the UN general secretary to assess the will of the Bahraini people with regards to their sovereignty. The survey (sometimes referred to as a "referendum") took the form of a United Nations poll on whether islanders preferred independence or Iranian control. The report of the Personal Representative of the Secretary-General on the consultation stated that "the overwhelming majority of the people of Bahrain wish to gain recognition of their identity in a full independent and sovereign State free to decide for itself its relations with other States." As a result, the United Nations Security Council unanimously passed Resolution 278 on 11 May 1970, while in the same month Iran renounced its claim to the island. The country subsequently became independent from the United Kingdom, declaring independence on 15 August 1971, and