In a survey conducted by the Peshawar Police, 636 schools were reported with lacking sufficient security arrangements. These included 463 privately-run institutions and 173 government schools.
Officials told that the survey of remaining schools in the provincial capital would be completed in two days.
The latest measure came in view of reopening of the schools after the deadly Peshawar school massacre which took place on December 16.
The incident had claimed the lives of 148 people, mostly children.