OTTAWA -- An Ottawa university is apologizing for accidentally sending out an alert about an "active attacker" on campus.

Carleton University says staff were updating the emergency messaging system on Monday when the incident happened.

The school says the message was sent when the alert template should have just been saved.

It was the second time in less than a week that students at Carleton got an emergency alert.

On Saturday, the school issued an email alert warning of a "hazard on campus" following a fire at the Steacie Building for Chemistry.

The alert advised students and faculty to evacuate the area.