Nato helicopters from Afghanistan attacked a militant-infested border region of Pakistan today, killing three Pakistani soldiers, a Pakistani official said.
A spokeswoman for the Nato-led International Security Assistance Force (ISAF) in Kabul said none of its helicopters had crossed into Pakistani airspace, however.
Pakistan has said it would consider "response options" if Nato forces continued to violate its sovereignty.
Two Nato helicopters today attacked Teri Mangal village in Kurram, an ethnic Pashtun tribal region in the Pakistani northwest, a Pakistani security official said.
"The helicopters shelled the area for about 25 minutes. Three of our soldiers manning a border post were killed and three wounded," the official said.
The attack if confirmed, would be the fourth cross-border raid in recent days, which comes just as the United States steps up strikes by unmanned drone aircraft in Pakistan's North Waziristan.
ISAF spokeswoman Maj Sunset Belinsky said the helicopters targeted militants in Afghanistan's eastern Paktia province, opposite Kurram, and they did not cross into Pakistan. But Pakistan military officials had informed ISAF that their border forces had been struck in the attack, she said in a statement.
"ISAF is working with Pakistan to ascertain if the two events are linked. The matter remains under investigation," she said.
Reuters