The Ministry of Defence has requested the help of the fire service to tackle blazes which started on the military ranges at Otterburn last week.
Two fires, thought to have been started by sparks from firing exercises last weekend, are still burning and have now spread outside the range area.
Last week, an MoD spokesman had said it was standard practice to allow fires to burn out on the training area, because of other ordnance on the range. The fire service would only be called in if it extended beyond the military area. The spokesman added there was no risk to the public and it was monitoring the situation carefully.
But due to high winds in the area, the MoD has now called in Northumberland Fire and Rescue Service to assist, with engines from Rothbury, Bellingham, Hexham and Ponteland deployed, including the 4x4 fogging units from Rothbury and Bellingham. The gate to the military road has now been closed to prevent members of the public from getting too close and getting into danger.
County councillor for the area, Coun Steven Bridgett, said: "The fires have begun to spread just outside of the impact area, so personnel can now be deployed to bring it under control. It is also understood that the fire has crossed the Burma road, mainly due to the winds.
"There is currently no danger to residents or homes and I’ve got every confidence that the Northumberland Fire and Rescue Service, working with its partners in the Ministry of Defence (as it has done so many times before), will be more than capable of dealing with the matter. If the situation changes, I will of course keep residents updated."
But Coun Bridgett also issued a warning to people thinking of sightseeing: "Could I remind spectators and visitors to stay out of the area, as it would appear the MoD are having to deal with a number of people who have gone up to ‘sightsee’?"
He added: "The Northumberland Fire and Rescue Service is one of the best trained fire and rescue services when it comes to dealing with wildfires. And let us not forget that military have helped on numerous civilian fires in our area in the past."
All of the county's fire appliances have been stood down except Bellingham, which will remain on site with the crew, to monitor and carry out dampening down on the periphery of the impact areas.
The fires are still largely confined to the military training areas where unexploded ordnance make it unsafe to send in firefighters. They continue to be monitored by the Ministry of Defence.
Coun Bridgett has been told by the county's Chief Fire Officer that Tactical Wildfire Advisors from the Service will remain at the disposal of the MoD for continued support and advice.
He said: "I've been told there is currently no risk to the residents and businesses within the training area nor in the Coquet and Rede valleys.
"I’m sure many will continue to have an opinion on the matter but I’m inclined to follow the advice of the people at the MoD, Fire and Rescue Service and the Environment Agency, who clearly know what they are doing in these types of circumstances.
"I will be speaking to the Chief Fire Officer tomorrow morning and will continue to receive updates over the next few days. As soon as I have anything further to report, I will of course update my residents."