Bushfire downgraded in northern NSW

A bushfire that had been threatening homes in northern NSW has been downgraded to watch-and-act.

Firefighters say smoke and embers will be visible around Kremnos as the blaze heads in a northerly direction towards Blackbutt Road, Curlew Drive and Sandstone Drive.

Firefighters worked overnight to protect homes and strengthen containment lines.

Five trucks and an aircraft were used on Saturday as strong winds fanned the bushfire, but cooler conditions are expected on Sunday.

Elsewhere on Saturday, police arrested a 16-year-old boy who's accused of deliberately lighting a fire that burnt through scrubland and came close to a shopping centre and homes near Killarney Vale on the Central Coast.