The Princes Highway has reopened between Mount Gambier and Dartmoor after a fire in Mumbannar on Thursday. 

The fire is contained but officers will remain onsite in coming days to look for spots and black out around the fire ground.

Incident controller David Chugg said the highway reopened Friday at 3.15pm with some restrictions.

“There's fire fighters on scene and their safety is a priority for us,” Mr Chugg said. “There will be a traffic management plan in place implemented by Vic Roads.

“Public safety is key and we ask the public to be mindful that there was a fire there and to obey the road signs.

“The fire fighters are doing some great work in the area at the moment. CFA and fire fighting management are in place for the next few days looking at any spots and monitoring the area over the next three to four days. 

Friday, 7.30am: Police say the bushfire at Mumbannar in now contained and under control.

But, the Princes Highway remains closed between Mount Gambier and Dartmoor. 

Thursday, 6pm: The bushfire at Mumbannar has been downgraded from an emergency warning to watch and act with houses no longer under threat.

Incident controller Andrew Morrow said the Princes Highway would remain closed overnight. 

"Houses are no longer under threat and we're hoping to contain the fire by midnight. Crews will work on that with support," he said. 

"The Princes Highway will be closed for some time because of hazardous tree risk and the safety of firefighters working on the edge of the road. The fire ran on the south side of the road for a lengthy section and some on the north side.”

He said crews would mop up and black out overnight and into Friday.

The fire is estimated to have burnt across 30 hectares but he said it would be closer to 45 to 50 hectares by the time the fire was fully extinguished. 

He said investigations into the cause of the fire would continue on Friday.

Update: 3.20pm

The Princes Highway is closed to traffic at Mumbannar as the CFA calls in more resources to fight a bushfire in the area. 

More than 20 crews are working to bring a fire under control on Palpara Settlement Road, Mumbannar.

Incident controller Andrew Morrow said more than 20 trucks and other vehicles were at the scene with more on the way, including a large air tanker en route from Avalon. 

Mr Morrow said a fire at Mumbannar began about 1pm Thursday at the site of an old mill and jumped into bushland under strong north-westerly winds.

"It’s spread under those winds almost parallel to the Princes Highway,” Mr Morrow said. “It's recently spotted over the Princes Highway and the highway is now closed and a traffic diversion is in place,” he said.  

“We have a significant amount of resources on the fire ground supported by six fire bombers and the large airtanker has been deployed from Avalon in support.

“We're hopeful that will make a difference in controlling the run of the fire in the immediate time. We'll work on control lines on the fire edge.

“We would have somewhere in the order of 20 tankers and other vehicles as well as dozers on the fire but there's more on the way.

He said residents had been advised to leave if safe to do so and the warning remained in place. 

He said the highway was closed between Dartmoor and Rennick as crews worked to contain the blaze.

VicRoads has advised the Princes Highway at Mumbannar near the Princess Margaret Rose Caves Road is closed to traffic.

"The road has been closed in both directions between Dartmoor-Hamilton Rd and the Glenelg Highway," according to a statement on the VicRoads website.

Motorists are advised there is a detour in place via the Dartmoor-Hamilton Road.

Earlier

Residents have been urged to flee an out-of-control bushfire as fire crews fight to bring a five hectare bushfire under control near Dartmoor.

Fourteen CFA crews are at the blaze, which began at 1.53pm on Thursday, 17 kilometres west of the town. 

The bushfire is travelling in a south-easterly direction towards Mumbannar and Wanwin and the CFA has urged residents in the area to leave immediately

"Mumbannar and Wanwin could be impacted anytime within the next six hours. Leaving now is the safest option," the Vic Emergency alert said on Thursday afternoon.

In a separate incident, 25 crews are working bring a building fire under control on Palpara Settlement Road, Mumbannar.

Two crews are also responding to a small fire on River Road at Nelson.

More to come