Thousands of supporters of Pakistan’s imprisoned former Prime Minister Imran Khan rallied on the outskirts of the capital, Islamabad, on Sunday, demanding his release. He has been in prison for more than a year in connection with more than 150 police cases. The demonstration, led by Khan’s Pakistan Tehreek-e-Insaf (PTI) party, is the largest in Islamabad since the retired international cricketer was jailed last year on several charges, some of them still before the courts. Protesters cleared containers used by Pakistani authorities to block major roads into Islamabad on Sunday before the demon…