International outrage grew Thursday at the shooting of a teenage Pakistani campaigner by the Taliban, with US President Barack Obama leading condemnation of the "disgusting" attack.
UN chief Ban Ki-moon also expressed horror at the attack on Malala Yousafzai, 14, who is in intensive care after she was shot in the head in broad daylight on a school bus on Tuesday, an assassination attempt that has appalled Pakistan.
It took place in Mingora, the main town of the Swat valley in Pakistan's northwest, where Malala had campaigned for the right to an education during a two-year Taliban insurgency which the army said it had crushed in 2009.
On Wednesday doctors successfully performed surgery to remove the bullet lodged near her shoulder, where it moved after entering her head, in a military hospital in the northwestern city of Peshawar.
Preparations were made to fly her abroad, but a military source told AFP she was currently too ill to travel. White House spokesman Jay Carney later said US forces were ready to offer transport and treatment to the teenager if needed.
Her uncle Saeed Ramzan said doctors told the family Malala was stable after the three-hour operation.
"But they said the next 48 hours are important and after that it will be decided whether she will be sent abroad or not," he told AFP at the family home in Mingora, which is under heavy police guard.
"We saw movement in her body today but she is still unconscious."
Obama described the shooting as "reprehensible and disgusting and tragic," Carney said, amid escalating international anger over the attack.
"Directing violence at children is barbaric, it's cowardly and our hearts go out to her and the others who were wounded as well as their families."
Ban was "deeply moved" by her campaign for education rights and called for "the perpetrators of this heinous and cowardly act to be swiftly brought to justice," his spokesman Martin Nesirky said.
-- 'Vile aggression' --
European Union foreign policy representative Catherine Ashton earlier condemned the attack as a "a vile aggression".
President Hamid Karzai of neighbouring Afghanistan, where a fierce Taliban insurgency is raging, telephoned his Pakistani counterpart Asif Ali Zardari to condemn the shooting, according to a statement from the Pakistani government.
"Such incidents of barbarity strengthen national resolve to fight militants to the finish," Zardari told the Afghan president.
Malala won international recognition for highlighting Taliban atrocities in Swat with a blog for the BBC three years ago, when the Islamist militants burned girls' schools and terrorised the valley.
Her struggle resonated with tens of thousands of girls denied an education by Islamist militants across northwest Pakistan, where the government has been fighting local Taliban since 2007.
She received the first national peace award from the Pakistani government last year, and was also nominated for the International Children's Peace Prize.
Doctors earlier confirmed the bullet had been removed from Malala's shoulder and Interior Minister Rehman Malik said she would remain in Peshawar until medics agreed she could be moved.
"Malala's condition is improving after the surgery and doctors will keep her in a state of unconsciousness for two days," Malik told reporters.
"Every effort has been made to ensure that she does not suffer brain damage. But anything can happen in such a situation."
There has been shock and revulsion in Pakistan, where schoolchildren across the country on Wednesday offered prayers for Malala's recovery and small protests against the attack were held in Mingora, Islamabad and the eastern city of Lahore.
Powerful army chief General Ashfaq Kayani visited Malala on Wednesday and said it was time to "further unite and stand up to fight the propagators of such barbaric mindset and their sympathisers".
The provincial government announced a 10 million rupee ($104,000) reward for information leading to the capture of Malala's attackers, who escaped after the shooting.
Commentators said the brazen shooting raises serious questions about why the government did not do more to protect Malala and about the Taliban presence in Swat, three years after the army said it had defeated the uprising.
Amid public outrage, the Pakistani Taliban issued a statement seeking to justify the cold-blooded murder attempt on a child, saying any female who opposed them should be killed.
Followers of the Taliban, who controlled much of Swat from 2007-2009, have destroyed hundreds of girls' schools across northwest Pakistan.
Taliban bombers have killed thousands of Pakistani soldiers and civilians over the last five years, but many in the country blame the United States and its 2001 invasion of neighbouring Afghanistan for the violence.