Wellington's Tawa College is out of lockdown, after police received a report of an incident involving a gun.
Police were notified of the incident at 9.20am, with the school putting itself into lockdown.
It has since been lifted.
Students at the school north of Wellington were locked down on Tuesday afternoon after a violent incident on school grounds.
Police said there was nothing to indicate that Friday morning's incident was linked to a stabbing on Tuesday, when one person was seriously injured and taken to Wellington Hospital's intensive care unit.
A 15-year-old was charged with wounding to intent to cause grievous bodily harm.