The death toll in a gun and explosives attack on a university in northwestern Pakistan has risen to 21, police told AFP, adding that security forces had ended the operation against the gunmen.

"The death toll in the terrorist attack has risen to 21," regional police chief Saeed Wazir told AFP without specifying if that included the four militants the army stated it had killed.  

He said the operation had ended and security forces were clearing the area, with most of the student victims shot dead at a hostel for boys on the Bacha Khan University campus in Charsadda.