China condemned "in the strongest terms" the terrorist attack on a school in Pakistan that left scores dead.

Taliban militants attacked an army-run school in Pakistan's northwest city of Peshawar on Tuesday afternoon, killing at least 137 people, many of them children, and injuring 245 others.

"We are deeply shocked and grieved by the attack and condemn it in the strongest terms," Foreign Ministry spokesman Qin Gang said on the ministry's website on Tuesday night.

China extended its heartfelt condolences to the victims' families and friends and expressed its deepest sympathy to the people of Pakistan, Qin said.

Qin said China opposes terrorism in any form and will continue to firmly support the unremitting efforts by Pakistan to fight terrorism, safeguard national stability and ensure the safety of its citizens.