A Nato helicopter has injured two people in the Pakistani region of North Waziristan, local officials say.
It hit a Pakistani checkpoint on the Afghan border in the Datta Khel area, Reuters news agency reports. A spokesman for Western forces in Afghanistan said it would investigate.
The reports come two weeks after Osama Bin Laden was killed by US commandos in the Pakistani town of Abbottabad.
Pakistan’s government condemned the violation of its sovereignty.
Last September, Nato aircraft crossed the border from Afghanistan in an attack which Pakistan says killed three soldiers. Subsequently Pakistan temporarily blocked a key Nato supply route from Pakistan into Afghanistan.
US drones also frequently strike the tribal areas along the Afghan border, which are are considered to be a haven for al-Qaeda and Taliban militants who launch attacks in Afghanistan.
Correspondents say only US forces have the capacity to deploy such aircraft, but that drone attacks have the tacit approval of the Pakistani authorities. Pakistani leaders deny secretly supporting them.
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