A ministry spokesperson told TBNewswatch the fire – designated Thunder Bay fire No. 8 – is east of the Kaministiquia River, about seven kilometres southeast of Sistonen's Corner near Sarri Road.
According to data provided online by the MNRF, at 5 p.m. the fire was estimated to have burned 120 hectares.
The spokesperson said that Oliver Paipoonge firefighters responded to the initial call.
Two CL-415 water bombers on loan from Newfoundland were picking up water at Dog Lake.
One helicopter was also assigned to the fire.
At 8:00 p.m., the ministry issued an update which said the fire was still listed as not under control but the size remained at 120 hectares.
Elsewhere in the Thunder Bay area, a 1.8 hectare fire near Dog Lake was also listed as not under control.