Walls riddled with bullet holes, an auditorium floor covered in blood and a burnt out office where a suicide bomber blew himself up – the first shocking images of the aftermath of the attack at a school in Pakistan have started to emerge today.

Journalists have been allowed into the building to record the destruction and full horror of the eight hour siege after seven Taliban gunmen bent on revenge stormed the military-run school in the north-western city.

The result was a series of images which show the full scale of the fighting and violence witnessed as the militants killed 148 people, including 132 innocent children.

Funerals for the victims were being held today as the nation started to mourn at the beginning of the official three day mourning period.

Pakistani video journalists film inside the auditorium of the Army Public School a day after an attack by the Taliban, in Peshawar, Pakistan (AP)

A local reporter walks past a wall full of bullet holes at the Army Public School (Reuters)

A Pakistani soldier walks amidst the debris the day after the Taliban attack at the school in Peshawar (AFP)

The attack at the Army Public School and College was the deadliest slaughter of innocents the country has witnessed.

In pictures: Aftermath of Taliban massacre in Peshawar Show all 12 1 /12 In pictures: Aftermath of Taliban massacre in Peshawar In pictures: Aftermath of Taliban massacre in Peshawar Army Public School A Pakistani soldier shows the media a burnt classroom at an army-run school a day after an attack by Taliban militants in Peshawar In pictures: Aftermath of Taliban massacre in Peshawar Army Public School A journalist reacts as he visits the Army Public School that was attacked by the Taliban militants in Peshawar In pictures: Aftermath of Taliban massacre in Peshawar Army Public School Pakistani security officials inspect the premises of Army Public School after the attack by the Taliban militants in Peshawar In pictures: Aftermath of Taliban massacre in Peshawar Army Public School Journalists inspect the premises of Army Public School In pictures: Aftermath of Taliban massacre in Peshawar Army Public School A view of a class room of Army Public School In pictures: Aftermath of Taliban massacre in Peshawar Army Public School A view of the blood stained auditorium of Army Public School that was attacked by the Taliban militants in Peshawar In pictures: Aftermath of Taliban massacre in Peshawar Army Public School Pakistani video journalists film inside the auditorium of an Army Public School a day after an attack by the Taliban, in Peshawar, Pakistan AP In pictures: Aftermath of Taliban massacre in Peshawar Army Public School Chairs are upturned and blood stains the floor at the Army Public School auditorium the day after Taliban gunmen stormed the school in Peshawar AP In pictures: Aftermath of Taliban massacre in Peshawar Army Public School A pair of glesses lays on the floor of the blood stained auditorium In pictures: Aftermath of Taliban massacre in Peshawar Army Public School Pakistan army soldiers stand outside the auditorium of an Army Public School a day after an attack on the school, in Peshawar AP In pictures: Aftermath of Taliban massacre in Peshawar Army Public School Pakistani journalists film and photograph inside an auditorium of the Army Public School attacked the day before by Taliban gunmen AP In pictures: Aftermath of Taliban massacre in Peshawar Army Public School A broken window of a class room of Army Public School

Prayer vigils were being held across Pakistan and in other schools, where students spoke of their shock at the brutal attack.

Taliban gunman broke into the school before opening fire and killing 132 children, wounding another 121 along with three staff.

The school's head Tahira Qazi was found among the debris overnight.

Pakistani security officials inspect the premises in the wake of the attack (EPA)

Pakistan army soldiers stand outside the school's auditorium the day after the Taliban attack (AP)

Military spokesman Major General Asim Bajwa said the school principal was inside her office when the attackers made their way into the administration building.

He said she locked herself into the bathroom but was killed after a grenade was thrown through a vent and into the room.

Army commandos fought the Taliban throughout the day until the school was cleared and all the attackers were reported to have been killed, eight hours after the siege had started.

The Pakistani Taliban, which is fighting to topple the government and set up an Islamic state, immediately claimed responsibility for the attack.

"We selected the army's school for the attack because the government is targeting our families and females," said Taliban spokesman Muhammad Umar Khorasani. "We want them to feel the pain."