The warning sirens were heard around the Tupapa and Titikaveka areas, where people took to social media questioning if it was just a drill or an emergency.
Emergency director Charles Carlson said they were testing early warning sirens, and this would continue today.
The drills were held annually, he said, though yesterday there were some minor hiccups.
The problems were with the automated system that activated the system from the office, otherwise it could be manually activated as required.
This was just part of a maintenance programme, he said. And in the Pa Enua, each island council tests its own sirens as well.
Today’s drills will continue between 8am to 4pm, taking 3 to 5 minutes for each siren.