Fires sweep close to Sydney mansions

A hazard reduction burn has swept close to some multi-million dollar mansions on Sydney's northern beaches.

Large flames were seen ripping through North Curl Curl's clifftop bushland as crews stood in backyards, monitoring the spread

Fire and Rescue NSW has claimed the burn is going according to plan and no homes are under threat.

The burn is set to be conclude at 5pm, with patrols continuing into the evening.

Fire and Rescue NSW advised residents with respiratory conditions to stay indoors and keep doors and windows closed.