At least five NATO helicopter gunships were seen flying near the Pak-Afghan border and two of them entered Pakistani territory in Torkham and Pasidkhel in Khyber agency bordering Afghanistan, security officials were quoted as saying by the media.
The helicopters crossed over through Shamshad mountains and remained in Pakistan's airspace for 10 minutes and returned without any action, Dawn reported.
Pakistan is yet to respond to the airspace violation and it has not been ascertained whether the incursion was deliberate or not during routine patrolling on account of rugged mountainous terrain.
A few days back, NATO had carried out a massive assault on Taliban positions in the Shamshad mountains and killed scores of Afghan Taliban militants.