A teenager is in custody after allegedly firing a gun at a private school in Perth’s northern suburbs.

West Australian police say the 15-year-old is understood to have fired one or more shots in the car park at Atlantis Beach Baptist College on Wednesday about 11.50am.

“We do not have any reports at this stage of anyone being injured,” Inspector Geoff DeSanges told reporters as the incident unfolded.

“I’d like to reassure everyone that we have significant police resources on-site.”

The school was placed in lockdown during the incident and police have since said there is no ongoing risk to the public.

All staff and students at the school have been accounted for.

Investigations are continuing.

With AAP and Aaron Bunch in Perth.