More than 120 people, mostly children, have been killed in a Taliban attack on a school in the city of Peshawar, in north-eastern Pakistan.

At around at 10:00 local time (05:00 GMT), six or more militants are reported to have scaled the walls surrounding the army-run school and launched an assault on the army-run school.

As many as 80 children are believed to have been killed in the attack, as the gunmen went room to room indiscriminately shooting at those inside. A number of loud blasts were also reported.

General Asim Bajwa of the Pakistani Army has said that they had killed six of the attackers, but their progress through the school building had been hampered by improvised explosive devices (IEDs) planted by the attackers.

The targeting of children has caused widespread shock in Pakistan, where the attack is one of the most deadly in recent years.

The Pakistan Army has said that the majority of the school’s 500 pupils have now been evacuated, but it is unclear how many are still being held hostage by the gunmen.

A student injured in the siege told NDTV from a hospital bed:

“As soon as we entered the hall, firing started behind us in the hall. Our teacher said close the doors. We closed the doors and suddenly they entered, breaking the doors… As soon as we hid under tables, they fired bullets at our legs and our heads and then they burned our madam. They burned our madam. The firing continued but we didn’t move because whoever moved got shot at.”

A helicopter is currently circling above the school and authorities have sealed of the major roads in and out of the city while victims are rushed to nearby hospitals by ambulance.

The Taliban immediately claimed responsibility for the attack, with spokesman Muhammad Umar Khorasani quoted as saying:

“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.”

A spokesman for the Taliban claimed the attack was a response to recent Pakistani military operations, with hundreds of Taliban fighters reported to have died in clashes in North Waziristan.

Pakistan Prime Minister Nawaz Sharif described the incident as a “national tragedy”, while opposition leader and former Pakistan cricket captain Imran Khan condemned the attack, saying:

“Shocked at attack on school in Peshawar. Strongly condemn this inhuman act of utter barbarism.”

Indian Prime Minister Narendra Modi also condemned the “cowardly terrorist attack”, saying:

“It is a senseless act of unspeakable brutality that has claimed lives of the most innocent of human beings – young children in their school.

“My heart goes out to everyone who lost their loved ones today. We share their pain & offer our deepest condolences”

Education campaigner and Nobel peace prize winner Malala Yousafzai, who was herself shot by the Taliban, has condemned the “atrocious and cowardly” attack:

“I am heartbroken by this senseless and cold-blooded act of terror in Peshawar that is unfolding before us.”