The top government official in Northwest Pakistan says Afghan-based coalition helicopters and commandos attacked a compound in a remote village near the Afghan border early Wednesday, killing at least 20 people.  Pakistan's military has confirmed an assault took place, but has not released any details.  VOA's Barry Newhouse reports from Islamabad.

Pakistani Governor of North West Frontier Province, Owais Ghani (File)

North West Frontier Province Governor Owais Ghani says three helicopter gunships and commandos based in Afghanistan raided homes in the Birmal area of South Waziristan, Wednesday morning.

The governor calls the operation "outrageous" and an assault on Pakistan's sovereignty.

Few details are known about the incident.

American officials in Pakistan and NATO officials in Afghanistan have not commented on the reported strike.  People in the area say foreign commandos operated on the ground during the raid and were flown in and out by helicopter gunships.  Pakistani media report some locals say the troops captured some people and took them away.

Pakistan Defense Minister Ahmed Mukhtar told reporters in Lahore that the country's foreign office is investigating.

He says he does not have details.  Mukthar says three houses were targeted by NATO forces and theorizes the strike had a specific target.

South Waziristan is considered to be a sanctuary for Taliban and al Qaida.  This year, a series of U.S. missile strikes have hit targets in South Waziristan and other Pakistani tribal agencies.  The Pakistani military rarely comments on the reported strikes, but local officials frequently condemn the action.

Wednesday's incident is the first time senior Pakistani security officials have claimed NATO troops carried out raids on Pakistani territory.  Pakistan's prime minister and other top officials have repeatedly insisted they will not allow foreign troops to operate inside Pakistan.