By Riaz Khan
Pakistanis have buried their dead and observed a day of mourning after Islamic militants stormed a university, gunning down students and teachers.
The death toll from the assault in the northern town of Charsadda has risen to 21, with another student dying in hospital, police say.
Most of the victims were Bacha Khan students. Two teachers were also among the dead, including a chemistry professor praised as a hero for shooting back at the attackers and allowing some students to escape.
"My son was grown up but still he was an innocent kid for me," said Gula Bibi, the mother of the second slain teacher, Iftikhar Ahmad, who was also the university librarian.
"My heart is breaking apart, I don't know what to do," she said.
The attack, which also wounded 22 students, raised grim echoes of the 2014 school massacre in the nearby city of Peshawar that left 150 dead, 144 of them children.
It yet again raised questions about whether security forces are able to protect the country's educational institutions from extremists.
Flags on official buildings and the national parliament were flying at half-staff and police stepped up security at schools and educational centres across the country.
A breakaway Taliban faction claimed responsibility for the assault – the same faction, headed by Khalifa Umar Mansoor, which had claimed the Peshawar school assault.
The university in Charsadda is named after one of Pakistan's greatest secular leaders who often espoused communist philosophy, Abdul Ghaffar Khan, also known as Bacha Khan.
The attack coincided with the 28th anniversary of Bacha Khan's death.
Most of the victims were buried quickly, according to Muslim tradition, with funerals overnight and early on Thursday (local time), said police official Tariq Khan.
A spokesman Mohammad Khurasani for the main larger Taliban group in Pakistan disowned the group behind the attack, terming it "un-Islamic".