ISLAMABAD: The Nat­io­nal Counter Terrorism Authority (Nacta) issued an alert for possible terrorist attacks during the towards Islamabad, reliable sources told . PTI is set to kick off its protests today (Sunday), for which extra security personnel have already been deployed in Islam­abad, Rawalpindi and several districts of Punjab. According to sources, the alert was issued after “technical and human” intelligence gathered by the apex counter-terrorism body revealed that terrorists were planning “major activities” in big cities of Pakistan. Multiple sources confir­med “necessary preparat­ions” by the terrorists in Afgh­a­n­istan, who “ent­ered into Pak­istan” on the night bet­ween Nov 19 and 20. They were expected to station themselves in big cities, the sources added. The terrorists, whom the government and the military refer to as Fitna-al-Khawarij, will possibly target the PTI’s protest “for their vested interest”, as per the sources. The Nacta has sugge­sted authorities ensure ex­t­reme vigilance and he­i­ghten security measu­res to prevent the att­ack.