KARACHI, 18 May — A number of opposition leaders, arrested on May 1 for trying to hold a rally, were released yesterday  following court’s order after the government failed to bring charges against them, officials said. Among those set free were former Governor Mamnoon Hussain, Mushahidullah, Shah Muhammad Shah, Saleem Zia, Tariq Khan and Miss Huma Mir — all belonging to the Pakistan Muslim League — and Khursheed Shah, Nisar Khuhro and Munawwar Suhrawardy of the Pakistan People’s Party. A PPP press release said party leader Benazir Bhutto welcomed their release. She urged the government to release all those detained on various charges. PPP leaders Makhdoom Amin Fahim, Aftab Shahban Mirani, Asfandyar Wali of ANP and several others were released earlier.