Taliban gunmen stormed a military-run school in the northwestern Pakistani city of Peshawar on Tuesday, killing at least 84 people, officials said, in the worst attack to hit the country in over a year.

The overwhelming majority of the victims were students at the army public school, which has children and teenagers in grades 1-10.

The horrific violence, carried out by a relatively small number of militants from the Tehreek-e-Taliban group, a Pakistani militant group trying to overthrow the government, also sent dozens of wounded flooding into local hospitals as terrified parents searched for their children.

“My son was in uniform in the morning. He is in a casket now,” wailed one parent, Tahir Ali, as he came to the hospital to collect the body of his 14-year-old son Abdullah. “My son was my dream. My dream has been killed.”

The attack began in the morning hours, with about half a dozen gunmen entering the school -- and shooting at random, said police officer Javed Khan. Army commandos quickly arrived at the scene and exchanged fire with the gunmen, he said. Students wearing their green school uniforms could be seen on Pakistani television fleeing the area.

Outside the school, shooting was initially heard along with one loud bang of unknown origin. Details were sketchy in the face of the overwhelming tragedy. Pakistani television showed soldiers surrounding the area and pushing people back. Ambulances streamed from the area to local hospitals.

Pervez Khattak, the chief minister of the province where Peshawar is located, said 84 died but that death toll could rise further in the unfolding drama.

Khattack said fighting was still underway in some parts of the school and that roughly the same number of students have been wounded. He said the 84 killed were all “children” but hospital officials earlier said at least one of the fatalities was a teacher and that one security official was also among the dead.

It wasn’t clear how many students and staff were still inside the facility. A student who escaped and a police official on the scene earlier said at one point about two hundred students were being held hostage. Both declined to be identified because they were not authorized to speak about the situation.

One of the wounded students, Abdullah Jamal, said that he was with a group of 8th, 9th and 10th graders who were getting first-aid instructions and training with a team of Pakistani army medics when the violence began for real.

When the shooting started, Jamal, who was shot in the leg, said nobody knew what was going on in the first few seconds.

 “Then I saw children falling down who were crying and screaming. I also fell down. I learned later that I have got a bullet,” he said, speaking from his hospital bed.

Another student, Amir Mateen, said they locked the door from the inside when they heard the shooting but gunmen blasted through the door anyway and began shooting.

The school is located on the edge of a military cantonment in Peshawar, but the bulk of the students are civilian.

There was conflicting information about how many attackers carried out the violence, but it was a relatively small number.

Taliban spokesman Mohammed Khurasani claimed responsibility for the attack in a phone call to media, saying that six suicide bombers had carried out the attack in revenge for the killings of Taliban members at the hands of Pakistani authorities. But the chief minister said there were eight attackers, dressed in military uniforms. Two were killed by security forces and one blew himself up, Khattak said. The rest were still fighting.

Peshawar has been the target of frequent militant attacks in the past but has seen a relative lull recently.

The Pakistani military launched a widespread military operation in the North Waziristan tribal area in June, vowing that it would go after all militant groups that had been operating in the area. With the launch of the operation, security officials and civilians feared a backlash by militants targeted by the military but until Tuesday a widespread backlash had failed to materialize.

Tuesday’s attack calls into question whether the militants have been crippled by the military or will be able to regroup.

The violence also underscored the vulnerability of Pakistani schools, which was dramatically exposed in the attack two years ago on Malala Yousafzai, a Pakistani girl shot in the head by a Taliban gunman outside her school in Swat Valley for daring to speak up about girls’ rights. She survived, becoming a Nobel Prize laureate and global advocate for girls’ education.

Militants have also blown up schools in the northwest. (AP)