China "strongly condemns" the terror attack on a university that killed more than 20 people in Pakistan, Foreign Ministry spokesman Hong Lei said on Thursday.

At least 22 people were killed at the university in Pakistan's northwest province of Khyber Pakhtunkhwa a day earlier, after a group of gunmen climbed the outside wall of the institution and cut the barbed wire fence to jump into the premises, Xinhua News Agency reported.

The Pakistan Taliban claimed the attack.

"China strongly opposes terror attacks against innocent civilians. It supports Pakistan in striking terrorism to maintain national stability and people's safety," Hong said.

The attack happened just over a year after more than 130 children were killed when Taliban militants attacked a school in Peshawar on Dec 16, 2014.