Islamabad, Aug 24 (IANS): Four Pakistani soldiers were killed and four others injured during an attack on a checkpost in Khyber Agency by militants from across the Afghan border, a military statement said.

Dawn online quoted the statement as saying that rockets were fired on Sunday at the Akhund Walah Pass checkpost. All the Afghan attackers were killed when the Pakistani troops returned fire.

The Pakistan foreign office summoned Afghan Ambassador Janan Mosazai on Sunday and lodged a “strong protest against the mortar shelling from Afghanistan in Khyber Agency, as a result of which four Pakistani soldiers were killed and four others were critically injured".

The Afghan envoy was asked to urge his government to investigate the incident.

“Such incidents do not augur well for the positive trajectory of relations the two sides have been able to achieve after sustained efforts,” the foreign officie said.

“Pakistan fully condemns terrorism in all forms and manifestations and is willing to collaborate with Afghanistan to fight the common enemy. However, the attacks against our military personnel are unacceptable,” it added.