GHALLANAI: Nato fighters killed 25 Pakistani military personnel in blistering air strikes on two Pakistani positions in Mohmand Agency in the small hours of Saturday. An army major and a captain were among the dead.

Islamabad reacted swiftly, closing the Torkham and Chaman border points to trucks carrying supplies for the Nato-led western forces in Afghanistan.

Western news agencies put the death toll at 28.

“We are investigating the incident,” a spokesman for the Army said, adding that the attack was unprovoked. “Troops responded immediately in self-defence to the Nato/Isaf aggression with all available weapons,” the Inter-Services PublicRelations (ISPR) said in a statement.

(Reuters news agency quoted a spokesman in Kabul as confirming that Nato aircraft had been called in to support troops during an incident near the border with Pakistan, and its forces were “highly likely” responsible for deaths of Pakistani soldiers.

“Close air support was called in, in the development of the tactical situation, and it is what highly likely caused the Pakistan casualties,” said Brigadier General Carsten Jacobson.

“We are aware that there are Pakistani casualties, we don’t know numbers, we don’t know the magnitude of the incident,” the Isaf spokesman said.)

According to officials, Nato helicopters attacked two remote border posts in Salala area in Baizai sub-district of Mohmand Agency before dawn on Saturday. The area is about 50km west of the regional headquarters of Ghallani.

The officials said the posts manned by regular army personnel had been set up to check militants’ infiltration into Pakistan from across the border.

The bodies of army personnel were airlifted to Peshawar.

Army chief Gen Parvez Ashfaq Kayani condemned the air strike as a “blatant and unacceptable act, resulting in loss of precious lives of Pakistani soldiers”, the ISPR statement said. “Lauding the effective response by the soldiers in self-defence, he directed that all necessary steps be undertaken for an effective response to this irresponsible act,” it added.

The statement said the army had lodged a strong protest with Nato/Isaf and called for immediate action against those responsible for the aggression. “The International Security Assistance Force (Isaf) is investigating the incident that occurred early this morning along the Afghanistan-Pakistan border,” the ISPR spokesman said.

Gen Johan Allen, the US commander of Isaf, offered condolences to the families of those killed in the attack and promised a thorough investigation into the incident.

“This incident has my highest personal attention and my commitment to thoroughly investigate it to determine the facts. My most sincere and personal heartfelt condolences go out to the families and loved ones of any members of Pakistan security forces who may have been killed or injured,” he said in a statement.

“The Isaf leadership remains committed to improving security relations with Pakistan, including coordination of operations along border regions in our united fight against terrorism,” it said.

Almost a similar attack in June 2008 had left 11 personnel of the Frontier Corps dead, prompting the government to suspend Nato supplies for a few days. The Nato-led Isaf and the Pakistan Army had conducted a joint investigation into the incident, but its findings remained unknown.