Questions rise about whether security forces are able to protect country's educational institutions

Pakistanis buried their dead and observed a day of nationwide mourning on Thursday following the brazen attack by Islamic militants who stormed a northwestern university the previous day, gunning down students and teachers and spreading terror before the four gunmen were slain by the military.

The death toll from the assault at Bacha Khan university in the town of Charsadda has risen to 21, after another student died in hospital, said police official Tariq Khan.