Pakistan fury over 'US assault'

Tension in Pakistan's north-west has increased in recent months

Pakistan has summoned the US ambassador to protest at an alleged cross-border raid which officials say killed at least 15 villagers in the north-west.

A number of civilians were reported killed in the raid, which Pakistan says was a violation of its sovereignty.

Correspondents say the raid appears to have been the first ever ground assault by foreign forces based in Afghanistan.

US-led and Nato forces said they had no reports of any such incursion. Border tensions have risen in recent weeks.

The BBC's Syed Shoaib Hasan in Islamabad says US aircraft have carried out air strikes in the region, but a ground assault would be unprecedented.

It is not clear who the target of any attack might have been.

Prime Minister Yousuf Raza Gilani said Pakistan would not allow any foreign power to carry out attacks on its territory.

He was speaking hours after his motorcade was hit by sniper fire near the capital, Islamabad. Senior government officials say he was not in the car at the time.

'Act of aggression'

Pakistani military and political officials say ground troops brought in by US-led coalition helicopters launched the attack in the South Waziristan tribal area near the Afghan border early on Wednesday morning.

Locals say soldiers attacked with gunfire and bombs. Women and children were among those reported killed.

Foreign Ministry spokesman Mohammad Sadiq said a "very strong protest" had been delivered to the ambassador, Anne Paterson.

"The ambassador said that she would convey it to her government," he said.

The army called the attack an act of aggression which undermined the fight against militancy.

North West Frontier Province (NWFP) Governor Owais Ahmed Ghani, who is in administrative charge of the tribal areas, called the attack "cowardly".

"At least 20 innocent citizens of Pakistan, including women and children, were martyred," he said in a statement.

There is mounting US pressure on Pakistan - a key ally in the "war on terror" - to crack down on militants, who use the border region to launch raids into Afghanistan.

The Afghan government and Nato say the border region is a haven for al-Qaeda and the Taleban. Pakistan says it is doing all it can to curb militancy.

On Monday, Pakistan's military suspended its operations against Taleban militants in the neighbouring Bajaur tribal area.

The government said this suspension of fighting was to respect the fasting month of Ramadan.

Taleban spokesman Maulvi Omar welcomed the announcement, but he said militants would not lay down their arms.