Kabul , Nov. 20 : At least six insurgent fighters have been killed and several others wounded following a suspected U. S. airstrike deep inside Pakistani territory on Wednesday, the Washington Post quoted a Pakistani security official as saying.

An unmanned U. S. Predator aircraft fired at least two missiles early Wednesday at a house near north Waziristan, one of seven semi-autonomous tribal territories that line Pakistan''s border with Afghanistan.

The latest incident holds significance, as airstrike in the district of Bannu in the North-West Frontier Province (NWFP) appears to be the first such attack outside Pakistan''s tribal areas.

The incident has come up on the sidelines of Pakistan''s army chief, Gen. Ashfaq Kiyani meeting with NATO officials in Brussels to discuss the cross-border missile strikes, which have been increasingly frequent in recent months and which the United States considers necessary for combating al-Qaeda and the Taliban.

A Pakistani security officer, requesting anonymity stated that the six persons who were killed were thought to be foreigners suspected of links to al-Qaeda, the Washington Post stated.

Details about the deceased individuals could not be confirmed, as the Pakistani military spokesman refused to comment and the United States generally does not acknowledge such attacks. It has not issued any public comments on the use of Predator airstrikes on Pakistani soil.

The recent attacks have drawn considerable public rebuke and stoked tensions in Pakistan.

Kiyani, who has publicly urged a halt to U. S. missile strikes in Pakistan, conferred with members of a NATO committee that included the organization''s top military commander, Adm. Giampaolo Di Paola of the Italian navy.

The United States has carried out an estimated 26 strikes on targets in Pakistan this year after getting frustrated by stalled progress in the seven-year-old war in Afghanistan and by an increase in attacks emanating from Pakistan, The Washington Post stated.

There have been at least 20 attacks that have occurred since August.

U. S. military officials privately tout the drone strikes, saying they have damaged insurgent safe havens in Pakistan''s rugged tribal areas, and have killed a number of al-Qaeda and Taliban commanders.

NATO supply routes from Pakistan into Afghanistan have become targets for Taliban fighters in recent months. Last week, a Taliban raid on a NATO convoy near the Khyber Pass shut down military supply traffic for several days.

The route had been reopened on Monday after Pakistani authorities assigned more security to the convoys. (ANI)