The Taliban is claiming responsibility for storming a military-run school in the north-western Pakistani city of Peshawar on Tuesday, killing at least 141 people and 132 children.
Pakistan's Major General Asim Bajwa said that another 121 students have been injured, after seven militants attacked the school on Tuesday morning, firing indiscriminately inside classrooms. At least one of the attackers blew themselves up.
"We selected the army's school for the attack because the government is targeting our families and females," Pakistani Taliban (TTP) spokesman Muhammad Umar Khorasani told Reuters. "We want them to feel the pain."
While the army managed to evacuate a large number of the hundreds of students and staff, an operation to clear the school of the militants and a small group of hostages lasted for several hours after the initial assault, as fighting and several explosions were reported.
Officials have confirmed that the siege has now finished and that all the militants had been killed, but troops continued to sweep the area for possible explosives. Bajwa added that: "There were about 1,100 students and staff who were registered in this school. Out of them, 960 have been rescued by our security forces."
Pervez Khattak, chief minister of Khyber Pakhtunkhwa province, which includes Peshawar, said that most of the student victims were between the ages of 12 and 16.
The TTP gunmen entered the school building at 10am local time on Tuesday morning and began shooting at random, according to police officer Javed Khan. Initial reports suggested the militants were wearing military uniforms but one student told Pakistan's Dunya TV: "The attackers had long beards, wore shalwar kameez and spoke Arabic."
Mudassir Awan, a worker at the school, said: "As soon as the firing started, we ran to our classrooms... They were entering every class and they were killing the children."
Another witness told Dawn News: "Later, army personnel ushered us out. While we were being moved out, we saw bodies of our classmates lying in the corridors."
This video, from Radio Free Europe/Radio Liberty, shows emergency services arriving on the scene as bystanders, some of them students, look on.
The army school is part of a network of 146 educational institutions across the country run by the Pakistani military and serves children of personnel and civilians between the ages of 10-18.
The TTP say that the raid was in retaliation for the ongoing military offensive launched in the summer, which the army estimate has killed 1,600 militants so far.
The Taliban spokesman, Khorasani, said: "We will target every institution linked to the army unless they stop operations and the extra-judicial killing of our detainees... now, families of the security forces should also feel the pain like our people... We have issued instructions to our armed men not to harm small children."
The Pakistani military's Zarb-e-Azb operation began in June and has targeted Taliban hotspots in North Waziristan close to the border with Afghanistan, and it has claimed widespread success in eradicating militancy from the region.
Pakistani army Lieutenant General Talat Masood, now retired and a military analyst, told VICE News that: "The Taliban have been weakened, their sanctuaries have been destroyed, and they are fragmented. They have lost the power to strike and have not been able to penetrate the hard targets and so have gone for a soft target.
"Today's attack has unified the nation and the reaction in Pakistan has been very strong," Masood continued. "Even those who've been on the sidelines are being forced to support the military. Imran Khan [leader of Pakistan's opposition PTI party] and the other politicians will also be forced to stand with the army."
Medical facilities in the region have been flooded with scores of victims, and hospitals in Peshawar put out appeals for blood donations.
Naeem Khan, a student and youth activist, told VICE News he heard about the attack on TV and immediately went to his nearest hospital to give blood.
He explained that the Combined Military Hospital is packed: "So many people are coming here to donate blood… A very lot of young people, from communities, colleges, and the public, I can even see a former minister of information, he also is donating blood."
Khan also told VICE News that there is a lot of fear in Peshawar. "It is very intense. We cannot explain the situation because little school children were attacked in their school. I have no words to explain the situation." He added, however, that he trusts the army to respond appropriately.
This footage, also from Radio Free Europe/Radio Liberty, shows scenes at the Lady Reading Hospital in Peshawar, with coffins for the victims arriving.
Meanwhile, Pakistan Prime Minister Nawaz Sharif announced a three-day mourning period, and traveled to the Peshawar region to oversee a response to the attacks.
"I can't stay back in Islamabad. This is a national tragedy unleashed by savages. These were my kids," Sharif said in a statement. "This is my loss. This is the nation's loss. I am leaving for Peshawar now and I will supervise this operation myself."
His counterpart in India, Narendra Modi, tweeted his condolences and strongly condemned what he described as a "cowardly terrorist attack."
It is a senseless act of unspeakable brutality that has claimed lives of the most innocent of human beings - young children in their school.
— Narendra Modi (@narendramodi)December 16, 2014
Indian children's rights advocate and joint 2014 Nobel Peace Prize winner, Kailash Satyarthi, described the events as marking "one of the darkest days of humanity."