Rescue operations continue at a school in Pakistan after Taliban militants stormed the building, killing 130 people, most of them students.
Islamist militants wearing military uniforms and strapped with explosives attacked the military-run facility in the northwestern city of Peshawar.
A provincial official said more than 120 others were wounded in the assault. VOA Dewaa Radio reporter Hameedullah said more than 100 of the wounded are children.
Provincial Chief Minister Pervez Khattak said most of the school building has been cleared, but some militants remain.
The Pakistani Taliban claimed responsibility for the attack, saying it was an act of retaliation for Pakistan's offensive targeting militants in the country's northwestern tribal region, near the Afghan border.
Prime Minister Nawaz Sharif condemned the assault, calling it a "national tragedy" and declared three days of national mourning.
Sharif, who arrived in Peshawar Tuesday, said the "government will not be deterred by this barbaric act" and vowed to continue military operations against the militants.
An army spokesman said later Tuesday that security forces have killed six militants. A search continues for others involved in the attack, he said.
Local officials said the death toll could rise and that over 100 of the dead were schoolchildren.
Authorities said heavily armed gunmen entered the school in a highly secured part of Peshawar city about 11 a.m. local time Tuesday and fired indiscriminately at students who were taking winter exams.
VOA reporter Hameedullah said the gunman shot students were were in the school garden and playground area. One of the gunmen then blew himself up.
The attackers took an unknown number of people hostage before Pakistan army commandos arrived at the scene and launched a rescue operation. Witnesses reported heavy gunfire from inside the school while ambulances ferried victims to hospitals.
The militant raid appeared to have caused most of the deaths in the beginning of the attack. Doctors said dozens of students are hospitalized, with some in critical condition. Authorities in Peshawar have appealed for blood donors.
Hameedullah, who reported from the scene of a Peshawar hospital, said, “A lot of people are donating blood.”
He said parents, rushing to the hospital where the bodies of many of the children were brought, were “weeping. They were beating themselves, there was sorrow." He added that there were "some moving scenes" at the hospital throughout the day.
Some students rescued
Ahsan Mukhtar, a student rescued by security forces, said, “As soon as the gunfire erupted, our teacher instructed everyone to move to a corner of the room for safety.”
Mukhtar added, “An hour later, when the intensity of the fire reduced, army soldiers arrived to rescue us, and on the way out, we saw bullet-ridden bodies of our schoolmates everywhere.”
Initially, Provincial Chief Minister Pervez Khattak said security forces shot dead two of the attackers while a third blew himself up.
Khattak said that most of the school building has been cleared, but some militants are still occupying the principal’s office and another nearby room.
The top provincial administrator added that the gunmen were dressed in the uniform of the Frontier Corps, a paramilitary force.
Taliban spokesman Muhammad Umar Khorasani told Reuters, "We selected the army's school for the attack because the government is targeting our families and females. We want them to feel the pain."
The Afghan border area, where Pakistan military operations are focused, has served as a major sanctuary and training ground for Pakistani and Afghan insurgents responsible for terrorist attacks on both sides of the mostly porous border.
Pakistani teenager Malala Yousafzai, joint winner of this year's Nobel peace prize for her education campaign work, said on Tuesday she was heartbroken by news of the attack. Malala, 17, was shot in the head on a school bus by the Taliban in 2012 and won global acclaim for her passionate advocacy of women's right to education.
"I am heartbroken by this senseless and cold-blooded act of terror in Peshawar that is unfolding before us," Malala, who now lives in central England, said in a statement. "Innocent children in their school have no place in horror such as this."
Elsewhere, India's Minister for Home Affairs, Rajnath Singh, said on Twitter, "This dastardly and inhuman attack exposes the real face of terrorism."
The United Nations in Pakistan strongly condemned "the barbaric attack," saying it is "appalled by this act of cruelty and brutality." A statement released by the U.N. resident coordinator in Pakistan said, attacking children and children’s education is a disregard of the most fundamental principles of humanity and we reaffirm our strongest commitment to protecting children’s rights.
Separately, U.S. Ambassador to Pakistan Richard Olson extended his country's "deepest sympathies and condolences to the victims, condemning the school assault as a senseless and inhuman" act.
British Prime Minister David Cameron tweeted on Tuesday: "The news from Pakistan is deeply shocking. It's horrifying that children are being killed simply for going to school."
VOA Dewaa Radio reporter Hameedullah contributed to this report from Peshawar, Pakistan. Some material for this report is from Reuters.