ISLAMABAD, Pakistan – Pakistan's army lodged a formal protest Friday to “allied forces” in neighboring Afghanistan over a suspected U.S. missile strike this week that killed 14 people in a Pakistani border village.

Army spokesman Maj. Gen. Athar Abbas said Pakistan concluded that Wednesday's attack on a house in Damadola village was launched by drones from Afghanistan.

Abbas said a formal protest was lodged Friday with “allied forces” in Afghanistan, an apparent reference to the NATO-led International Security Assistance Force that is fighting the Taliban-led insurgency there. The U.S. is among the nations contributing to ISAF.

Abbas said 14 people died in the attack.

It was unclear if any foreign militants were killed because local tribesmen had sealed off the area in the aftermath and buried the victims, he said.

Islamist parties, regional lawmakers and the governor of Pakistan's volatile North West Frontier Province have already condemned the attack as a violation of the country's sovereignty. Gov. Ovais Ahmed Ghani warned that it would undermine public support for Pakistan's efforts against terrorism.

It was the first such strike since Pakistan's new civilian government took power six weeks ago. A similar air strike in 2006 by a CIA drone targeted, and missed, al-Qaeda's No. 2 leader, Ayman al-Zawahri.

The government's response so far has been low-key, suggesting it may be extending the kind of cooperation to the U.S.-led fight against al-Qaeda as the former administration of President Pervez Musharraf.

But in a sign of tensions such attacks can spark, Islamic militants killed a Pakistani paramilitary soldier in revenge for the attack.

Authorities found the bullet-riddled body of the soldier early Friday about 6 miles north of Damadola. Mawaz Khan, a local government official, said a letter found near the soldier's body explained that militants killed him to avenge the strike.

Khan said the note included a warning for tribal elders that they would meet the same fate if they cooperate with Pakistani authorities.

The letter was issued in the name of Tehrik-e-Taliban Pakistan, a militant umbrella group whose deputy leader, Faqir Mohammed, has threatened to target Americans to avenge the strike. Mohammed is considered an associate of al-Zawahri.

However, a spokesman for the group has said it would continue with peace negotiations opened by the new Pakistani government.

The talks are regarded with apprehension by Western officials who are concerned a peace deal could give militants more freedom to mount raids into Afghanistan or plot terrorist strikes further afield.

Associated Press writer Habibullah Khan in Khar contributed to this report.