Maulana Fazlur Rehman Khalil, a US-designated terrorist and founder of the terrorist organisation Harkat-ul-Mujahideen (HuM), and close associate of Masood Azhar joined Imran Khan’s Pakistan Tehreek-e-Insaf (PTI) on Thursday, in an attempt to get political safeguards amid increasing pressure on Pak to act against terror operatives.