Eight hours after militants stormed a school in Peshawar, the siege ended with six dead Taliban terrorists.

"The combat operation has ended, security personnel are conducting clearing and hopefully clear the building at a time," said police officer Abdullah Khan.

Health Secretary Khyber Pakhtunkhwa Mustaq Jadoon said the death toll has risen to 135, with 114 wounded.

The bloodiest terrorist attack in Pakistan in the year, began Tuesday morning when heavily armed Taliban suicide bombers attacked an army school run and took several hostages, a throwback to the taking of the 2004 Beslan school by Chechen rebels.

A group of eight Arabic-speaking attackers dressed in paramilitary Frontier Corps uniforms, entered the Army Public School Warsak Road around 10:30 am local time and began slaughtering innocents, spraying bullets indiscriminately, from classroom classroom.

They also took several hostages using them as human shields. The death toll in the attack has reached 130, with most of them students, officials said.

They said all the militants have been killed - four of them blew themselves up while two were shot dead by security forces .. The Tehreek-e-Taliban Pakistan has claimed responsibility for the attack, one of the worst in recent years.

The Taliban spokesman said six suicide bombers attacked the army school, saying it was revenge for the army operation against militants in the tribal area of North Waziristan near Peshawar. "We feel our pain," said the spokesman.

World leaders joined together to condemn the attack as prime minister Nawaz Sharif called "national tragedy" and chaired a security meeting in Peshawar, where he was informed about the attack and operation.

Sharif reiterated that the military operation "Zarb-e-azab 'to chase terrorists tribal belt of the country will continue." It is a great act of cowardice ... the country must unite to fight terrorism, "he added.

General Raheel Sharif Chief of Army also reached Peshawar to control the situation.

In one of the worst attacks in recent years against children anywhere in the world, the militants were shooting in the classroom to classroom indiscriminately surprised students, eyewitnesses told local media.

A student rescued told reporters that the attackers had long beards and wore 'salwar kameez'. He said he spoke Arabic and seemed to foreigners.

In the incident in Beslan, North Ossetia, Russia, at least 32 armed men stormed a school and took more than 1,000 hostages, most of them children. More than 330 people, mostly children, died in the assault.

About 500 students and teachers believe that within the school when the attack began.