Five civilians and seven militants have been killed in north-west Pakistan in a suspected US missile attack, local officials say.
Missiles hit two buildings near Miranshah, the main town in the North Waziristan region on the Afghan border.
It has emerged that President Bush recently authorised US raids against militants in Pakistan without prior approval from Islamabad.
There is growing concern in Pakistan over unilateral US military action.
Early reports said all, or nearly all, of the dead were Taleban fighters killed by one missile.
But later reports from the scene said missiles hit two buildings - in one three women and two children were killed, and in the other seven Taleban militants died.
The missiles were fired from a drone - an unmanned US plane - local people said.
Military spokesman Maj Murad Khan confirmed "a missile attack at around 5.30 in the morning" and said the government had been informed.
Tensions in the border region are rising
American and international troops are fighting Taleban and al-Qaeda militants close to the scene of the attack in neighbouring Afghanistan.
Meanwhile, the Pakistani army says its troops have killed at least 28 militants in the north-west of the country.
The BBC's M Ilyas Khan in Pakistan says that heavy fighting is continuing around the strategically important area of Loisam in the Bajaur tribal area.
Friday's missile attack was in the Tol Khel area on the outskirts of Miranshah, local officials and eyewitnesses told the BBC.
Fighting in Bajaur has escalated in recent days
It is the fifth time since the beginning of this month that US forces have carried out cross border strikes, according to local people.
On Monday, at least 14 people were killed and 15 injured in a suspected US missile strike in North Waziristan, witnesses and officials said.
The attacks follow persistent US accusations that Pakistan is not doing enough to eliminate Taleban and al-Qaeda sanctuaries in the border region.
An unnamed senior Pentagon official told the BBC that at some point within the past two months President Bush issued a classified order to authorise US raids against militants in Pakistan
Pakistan has said it will not allow foreign forces onto its territory and that it will vigorously protect its sovereignty. It says that cross border raids are not the best way of fighting the "war against terror".
The country's Chief of Army Staff, Gen Ashfaq Parvez Kayani, said there was "no question of any agreement or understanding with the coalition forces whereby they are allowed to conduct operations on our side of the border".
The upsurge in strikes has alarmed Pakistani military and government officials, who say it seriously undermines their counter-insurgency operations.
Meanwhile, the Pakistani army says it killed at least 28 militants in the north-west of the country on Thursday night.
The US says militants are hiding out in north-west Pakistan
They said two army soldiers were also killed in the fighting. The killings took place in the troubled districts of Swat and Bajaur, on the Afghan border.
The militants have disputed the army's claim, saying no Taleban have been killed.
An army spokesman, Major Murad Khan, told the BBC that those killed included foreign fighters as well.
A Taleban spokesman, Maulvi Omar, told the BBC's Urdu service that no Taleban fighter had died in Thursday's fighting.
The casualty figures could not be independently verified.
Bajaur is believed to be a major al-Qaeda sanctuary, and has attracted several suspected US missile attacks from across the border in Afghanistan.
Security forces launched an operation against militants in the area in the first week of August.
Most markets and shops in the area have remained closed since then.
More than 300,000 people have since fled the area to avoid fighting.
Witnesses say those who are still in the area are faced with severe food and medicine shortages.