ISLAMABAD: Pakistan has extended a ban on Indian-registered aircraft from using its airspace until late March, the Pakistan Airports Authority (PAA) said on Friday, prolonging restrictions that have disrupted flight routes for Indian airlines. Pakistan first imposed the restriction on Apr. 23 last year as part of a series of tit-for-tat measures announced by both countries days after an attack in Indian-administered Kashmir. New Delhi blamed the attack that killed 26 tourists on Pakistan, Islamabad denied it.