NSW Central Coast bushfire may be arson

A bushfire in a NSW Central Coast national park that threatened properties may have been deliberately lit.

The Sunday evening blaze burned about three hectares of bushland in Brisbane Water National Park before it was brought under control by firefighters.

Locals have told police four male youths were seen in the area around the time the fire started.

Police are calling for anyone who may have seen anything suspicious or have any information to contact them.