Bangladesh was a part of Pakistan as East Pakistan when the Islamic Republic of Pakistan was born in 1947. It was composed of the Muslim part of Bengal. Although there are some improvements in East Pakistan, most Bangladeshis resent their domination by West Pakistani officials. The Awami League was the leading movement in East Pakistan, demanding equal rights for East Pakistanis. Agitation continued in 1960s, and its leader Sheikh Mujibur Rahman was jailed in 1966, only to be released in 1969 after a popular uprising. The 1970 Bhola cyclone destroyed the coast of East Pakistan, costing half a million lives, and the poor response of the central government only incensed the Bengali population. Pakistani president Abdul Yahya Khan had Mujibur arrested in 1971 and launched Operation Searchligh