Nobel peace laureate Malala Yousafzai, who was shot in the head by the Taliban in 2012, said she was "heartbroken" by "the senseless and cold blooded" killing of scores of children by Taliban militants Tuesday in Pakistan.

At least 130 people, most of them children, were killed when gunmen stormed an army-run school in Pakistan's northwestern city of Peshawar in an act that drew swift global condemnation.

"I am heartbroken by this senseless and cold blooded act of terror in Peshawar that is unfolding before us. Innocent children in their school have no place in horror such as this," Malala said in a statement.

"I condemn these atrocious and cowardly acts and stand united with the government and armed forces of Pakistan whose efforts so far to address this horrific event are commendable."

Seventeen-year-old Malala, who now lives in Britain, became a global icon after she was shot and nearly killed by the Taliban in her native Pakistan in October 2012 for insisting that girls had a right to an education.

The Tehreek-e-Taliban Pakistan (TTP) claimed responsibility for the attack as retaliation for a major military offensive in the region, saying militants had been ordered to shoot older students.