A 14-year-old teen who was shot by the the Taliban earlier this week is in a critical condition after surgery, CNN reports.
Malala Yousafzai was airlifted to the country's top military hospital for specialist treatment overnight.
One of the Malala's doctors told CNN that in the last eight hours her condition deteriorated, as she is now suffering from a condition called cerebral edema, which is a swelling of the brain, becuase of accumulation of water.
Malala's uncle told CNN the family is worried but hopeful.
The shooting of Malala Yousafzai on a school bus in the Swat valley has been denounced worldwide and by the Pakistani authorities, who have offered a reward of more than $100,000 for the capture of her attackers.
Two of her friends were also injured in the attack, carried out as retribution for Malala's campaign for the right to an education during a two-year Taliban insurgency in Swat that the army claimed to have crushed in 2009.
But as she spent a second day in intensive care questions are mounting about how the attack could have happened in the first place and how the perpetrators simply walked away in an area with a police and army presence.
"Now she needs post surgery care. The doctors recommended that AFIC (Armed Forces Institute of Cardiology) has better facilities for post-surgery care," military spokesman Major General Asim Saleem Bajwa told AFP.
Another official later confirmed she had arrived by helicopter in Rawalpindi, the twin city of the capital Islamabad and the headquarters of the Pakistan army.
Bajwa said Malala was unconscious and that the next 24 hours would be crucial.
On Wednesday, she underwent an operation to remove the bullet from between her shoulders in a military hospital in the northwestern city of Peshawar.
"She has been put on a ventilator for two days. The bullet has affected some part of the brain, but there is a 70 percent chance that she will survive," one of her doctors, Mumtaz Khan, told AFP.
Mehmoodul Hasan, one of Malala's relatives, said the family had been told doctors were sending her medical reports abroad for advice.
"They are checking if better facilities are available in the UK or Dubai or any other country, then they will decide about sending her abroad, otherwise they will treat her here," said Hasan.
US President Barack Obama, UN chief Ban Ki-moon and Pakistani leaders have expressed horror at the attack on a girl who won admiration for daring to speak out during the Taliban insurgency, which the army said it had crushed in 2009.
Malala won international prominence after 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 before the army intervened.
She was just 11 then, and 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.
The Pakistani provincial government announced a 10 million rupee ($104,000) reward for information leading to the arrest of Malala's attackers and Interior Minister Rehman Malik has promised to catch the gunmen.
He appealed to Pakistanis to pray for Malala's recovery on Friday, when Muslims say their main weekly prayers at mosques.
In northwest Khyber Pakhtunkhwa province where the attack took place, government spokesman Mian Iftikhar Hussain said that civil servants and schools would observe a one-minute silence on Friday to remember acts of terrorism.
Officers in Swat say dozens of people were rounded up after the attack but no one has been charged.
Local residents say four businessmen and outspoken anti-militancy advocates have been shot in Swat in recent months, raising fears about the scenic valley which Pakistan has been trying to restore as a tourist destination.
Mingora police station chief Ahmad Shah told AFP that nearly 200 people had been detained over Malala's shooting, including the bus driver and a school watchman, but that most had been released.
Despite a call from the army chief General Ashfaq Kayani to unite against militants and their "barbaric mindset," commentators expect little to change.
Many in the country blame the United States and the war in neighbouring Afghanistan for the violence. The military has been accused of playing a double game in supporting or at least accommodating Islamist militant groups.
The Taliban, who have killed thousands of people across Pakistan in the last five years and destroyed hundreds of girls' schools, have issued a statement saying that any female who opposes them should be killed.
