Afire north of Mount Gambier is still being monitored by emergency services this morning.

The blaze started in Honan Native Forest Reserve just before 1pm yesterday, with 17 fire crews and six aircraft called in to battle the flames near Wandilo and Glencoe.

Thirty Country Fire Service volunteers were joined by forest industry personnel to fight the scrub fire, which burned through three hectares of the reserve.

The CFS issued a warning for residents in the area at the height of the blaze, advising that smoke was impacting roads in the vicinity, possibly reducing visibility.

Just before 4pm the CFS advised that while the fire was still burning, the threat in the area had been reduced, however people are warned to look out for falling trees and branches near the fireground.

A CFS spokesperson said Department of Environment and Water staff managed the fire overnight and will continue to monitor it this morning.