A Pakistani student shot and killed his school principal on Monday, in a dispute over the student skipping classes to attend rallies supporting the country's strict blasphemy laws, a police official said.

Sareer Ahmed, principal of the private Islamia College in the northern town of Charsadda, had an argument with one of his students for missing a number of classes. The student then shot the principal on campus, local police chief Zahoor Afridi told Reuters.

He said the unnamed student had attended a sit-in staged by a new ultra-religious political party, Tehreek-e-Labaik, late last year to oppose a small change in wording to an electoral law, which it said amounted to blasphemy. The protest, which brought the capital Islamabad to a standstill, ended in clashes between police and demonstrators that killed seven people.

Police have taken the student, who appeared to be 16 or 17 years old, into custody and filed a first information report against him. In a video recorded during the arrest, the student can be heard defending his actions.

There have been at least 67 murders over unproven allegations of blasphemy since 1990.