Chasing militants of the Haqqani network, NATO helicopters carried out at least two airstrikes in Pakistan killing more than 53 Taliban fighters, after insurgents had attacked an Afghan security outpost near the border.
The helicopter gunships trained their guns on Haqqani militants at least six kilometres inside Pakistan on Saturday after the insurgents had attacked an Afghan army outpost.
"The ISAF helicopters did cross into Pakistan territory to engage the insurgents," NATO commanders were quoted as saying by the US media and the commanders defended their action saying that they had a right to self-defence.
"The strike killed 49 militants," an ISAF spokesperson said.
The helicopters returned to the border area yesterday when they were attacked by small fire by insurgents from North Waziristan in Pakistan.
"The gunships struck back at the insurgents engaging them and killed four militants," the spokesperson said.
The tribal areas in Pakistan's North Waziristan where the airstrikes took place is controlled by the Haqqani network and fighters of the Taliban commander Hafiz Gul Bahadur.
Washington, New York Times reported has been pressing Islamabad to launch military offensive against the Haqqani network.
This is the first time that US manned aircraft have carried out airstrikes in North Waziristan, where earlier Washington has been using unmanned drones to attack Taliban militants.
The NY Times quoting Pakistani military officials said two more NATO helicopters carried out a third strike inside Pakistani territory today killing five militants and wounding nine others.
The helicopters bombed and fired missiles at a village in the Khurram tribal area which faces Afghanistan's Paktia province.
Washington has branded the rugged tribal area, which lies outside Pakistani government control, a global headquarters of Al-Qaeda and the most dangerous place on Earth.
The Americans have carried out 19 missile strikes in this area in last 24 days killing around 90 people. While stepping up drone attacks, the US and NATO special forces, have simultaneously been carrying out hit and run raids on the Haqqani network in Afghanistan.