Pakistanis are unnerved in the wake of a brazen attack by militants at Bacha Khan University in Charsadda, Pakistan. On Wednesday, gunmen stormed the university grounds and started gunning down students and teachers, killing 21. A breakaway faction of the Taliban has claimed responsibility and on Friday threatened to carry about more attacks on schools and universities.
"There's a great sense of shock," says the BBC's Shaiima Khalil, who visited the site of the attack on Thursday. She couldn't get onto the university grounds because they had been closed indefinitely. "We were surrounded by heavily armed security personnel. There was a huge media presence, but the atmosphere was quiet tense. It was quite somber."
Pakistanis are sad, confused and angry because Wednesday's attack was similar to the massive slaughter carried out by militants in December 2014 at an army-run public school in Peshawar. At least 141 people died in that seige, including many children.
"There's a sense of 'Why is this happening again,'" says Khalil. "It's still quite shocking, the ease with which militants can get into an educational institute like this one and just start firing."
A chemistry professor at Bacha Khan University, Syed Hamid Hussain tried to stop the attackers and caught the attention of social media. He's now known as this hero in the white cape, a reference to the white jacket he wears as a science professor.
After the Peshawar attack in 2014, Pakistan improved school security. They built higher walls, installed barbed wire and started a program to arm teachers. Khalil says Hussain was one of them. "He fired at the attackers, but eventually he lost his own life which begs the question, how feasible is it if the teachers are armed that they can protect themselves and their students?"
Khalil says the reaction to Wednesday's attack is different from the way the country reacted in 2014. "It's really interesting. While a year ago there was huge support for the army saying, 'go get the attackers, go get those militants, hang them all.' The mood this time is quite different. There's a lot of grief, a lot of anger, but also questions are being asked about what the army has achieved."
Since the 2014 militant assault on the school in Peshawar, the Pakistani government reinstituted the death penalty and started trying suspects in military courts. And the public was totally behind it.
"They were all being set up in the name of national security, in the name of fighting terrorism, in the name of not having another attack on another school or another soft target," says Khalil. "And here we are. Another school attack. Another very soft target and people are asking why is this still happening?"
Pakistani President Nawaz Sharif has announced a huge deployment of troops to the border with Afghanistan to prevent infiltration of militants. But Khalil says that may not address the problem.
"The concern is whether the militants have actually dispersed from their big havens in North Waziristan and have now gone underground locally and are able to carry out these attacks."
UPDATE: This story has been updated to include new information about a breakaway faction of the Taliban claiming responsibility.