Lahore- Prime Minister Nawaz Sharif and Pakistan Tehrik-e-Insaf Chief Imran Khan are under threat of terrorist attacks as both are backing Operation Zarb-e-Azb against terrorists in the North Waziristan. According to details, Punjab Home Department has written a letter to police and other security agencies, asking them to beef up security of PM Nawaz Sharif and PTI chief Imran Khan as Taliban commanders Omar Khalid Khorasani and Commander Abdullah are planning attacks on both the leaders for backing Operation Zarb-e-Azb.