The South African government on Tuesday condemned a terrorist attack in Pakistan which killed 130 people, mostly children, the department of international relations said.

"The South African Government has today... joined the international community in condemning in the strongest possible terms the inhumane and barbaric terrorist attack against a school in the city of Peshawar," spokesman Clayson Monyela said in a statement.

"Deliberate attacks against schools and denying children the right to an education are contraventions of well-established international human rights and humanitarian law and constitute a crime against humanity."

Dirco extended their condolences to the people of Pakistan and said South Africa would continue to support efforts to address terrorism.

Taliban militants stormed an army-run school in the north west of Pakistan on Tuesday.

Witnesses described how a huge blast shook the school and gunmen went from classroom to classroom shooting children.