Khyber Agency- Two gunship helicopters belonging to the NATO-led international coalition forces have violated the airspace of Pakistan, according to security officials.

The officials quoted by local media agencies have said that the helicopters remained in the Pakistani territory for at least ten minutes.

The two helicopters that violated the Pakistani airspace were among five which were patrolling along the Pak-Afghan border in Torkham and Pasidkhel, the officials said.

The NATO-led coalition security forces have increased drone strikes in tribal regions of Pakistan during the recent days. At least 29 suspected militants were reported to be killed following a series of drone strikes in North and South Waziristan tribal regions last week. Pakistani officials also said that a major air assault was carried out by NATO on Taliban hideouts recently in Shamshad mountains located between Pakistan and Afghanistan.