Security forces have ended a gun and bomb attack on a university in north-west Pakistan in which 19 people were killed and 50 injured.
Four suspected attackers also died in a battle that lasted nearly three hours at Bacha Khan University in Charsadda.
There are conflicting reports about whether Pakistan Taliban militants carried out the assault.
The group killed 130 students at a school in the city of Peshawar, 50km (30 miles) from Charsadda, in 2014.
About 3,000 students are enrolled at Bacha Khan but hundreds of visitors were also expected on Wednesday for a poetry event.
Prime Minister Nawaz Sharif said in a statement, quoted by Reuters news agency: “We are determined and resolved in our commitment to wipe out the menace of terrorism from our homeland.”
It could have been much worse – M Ilyas Khan, BBC News, Islamabad
There have been conflicting claims about who could be involved in the attack, especially given a kaleidoscopic mix of militant networks that is evolving along the Pakistan-Afghan border region in the north.
The attack comes amid a sudden spike in militant violence in Pakistan, after a year of relative peace and quiet largely attributed to a 2014 military operation against militant sanctuaries in Waziristan. Questions are now being raised over whether that operation really destroyed the ability of militants to regroup and strike at will.
The attack is reminiscent of the December 2014 attack on a school in Peshawar in which more than 150 people, mostly schoolboys, were killed. But damage to life and property this time has been much less, mainly due to swift action by the local police, but also because of the fact that the university had its own team of more than 50 trained security guards on duty who first confronted the attackers.
A dense fog that reduced visibility to less than 10m may also have been a factor, as one police officer explained, because it put the attackers at a disadvantage against the university guards who knew the premises better.
“The operation is over and the university has been cleared,” Pakistani army spokesman Gen Asim Bajwa told Reuters news agency. “Four gunmen have been killed.”
The attackers struck at around 09:30 local time (04:30 GMT), apparently climbing over a back wall under cover of the thick winter fog.
Intense gunfire and explosions were heard as security guards fought the attackers.
“I personally heard two explosions,” an unidentified eyewitness told Pakistan’s Geo TV.
“We don’t know if they were suicide bombers or grenades. I personally saw two explosions and smoke was rising.”
Students and staff ran to find cover in toilets and examination halls.
Geology student Zahoor Ahmed said his chemistry lecturer had warned him not to leave the building after the first shots were fired.