Chairman, Pakistan Tehrik-e-Insaf (PTI), Imran Khan, on Sunday warned that if the CIA-operated drone attacks inside Pakistan were not stopped, PTI will stage a sit-in in Karachi to stop supplies to NATO and ISAF forces in Afghanistan as a protest against the attacks. Talking to newsmen after a meeting with Mumtaz Bhutto, Chairman Sindh National Front (SNF), he said that innocent people including women and children were being killed mercilessly in these attacks. He said that the drone attacks instead of curbing terrorism were breading terrorism and extremism in the country.