At least 19 people have been killed after gunmen stormed the Bacha Khan University in the north west city of Charsadda.
Umar Mansoor, a commander from the Pakistani Taliban said four of its suicide attackers were responsible but a spokesperson for the group disputed his claim. +
Local reports say the attackers used the cover of thick winter fog to make their way into the university
Prime Minister Nawaz Sharif said those who carried out the attack 'have no religion' and said his government would 'eliminate them'.
The flare up in violence along the border of the contested Kashmir region came as India prepared to mark the 50th anniversary of the 1965 war between with Pakistan.
Both sides blamed the other for Friday's exchange of fire.
Hong Xudong was abducted in May 2014 while travelling on his bicycle in the Dera Ismail Khan district - Pakistani security forces are said to have carried out a rescue operation, but details are limited.
While a Taliban splinter group claimed responsibility for the kidnapping, BBC News say it is unclear exactly which group was involved.
- The heatwave has coincided with load-shedding of electricity supply in Sindh, with some areas facing up to 20 hours of supply disruption a day according to some accounts.