Two teenagers on the run across Canada are at the "end of the road" as authorities close in on them.

Bryer Schmegelsky, 18, and Kam McLeod, 19, have been running from the scene of three murders in northern British Columbia for more than a week.

They have travelled east through three provinces and were last seen on Monday night at Gillam, in Manitoba, almost 3000km from Liard Hot Springs where Australian man Lucas Fowler and his American girlfriend Chynna Deese were brutally murdered.

The pair are suspected of killing a third person, a man aged in his 50s, before ditching and burning their red and grey Dodge pick-up truck.

They later did the same to a Toyota Rav-4 they had been travelling in, Royal Canadian Mounted Police say.

The latest sighting of the pair was in Gillam, a tiny town with a population of 1200 people described by the local mayor as "the end of the road" because there's one way in and one way out.

The teens purchased petrol from a town called Split Lake, which is two hours by car from Gillam. There, they spoke with an attendant who described them as calm.

CCTV of Lucas Fowler and Chynna Deese at a petrol station in Fort Nelson on July 13. Photo / AP

She said McLeod paid for $20 worth of petrol but Schmegelsky asked a strange and very casual question — whether he could consume alcohol in the dry community.

"The guy who paid for the gas — he was quiet, he didn't say anything, he was just looking down," Mychelle Keeper told CBC News.

"They seemed like, I don't know, normal. I'm just so nervous right now thinking about it."

Police today confirmed the grey vehicle that was burnt out by the side of a road had been driven by the pair.

Sergeant Janelle Shoihet spoke with the Today show from Manitoba, confirming the latest sighting was in a "very rural part of Canada".

"The last confirmed sighting was on Monday evening," she said.

"That was in Gillam, Manitoba, which is a very rural part of Canada. The northern part of Manitoba.

"It is my understand only one major roadway into that area. Our investigators in that area have now set up a checkpoint to allow people to check people going in and out of the area in an effort to locate Kam and Bryer."

Sgt Shiohet reiterated locals should not approach the pair as they are considered armed and dangerous.

"We want to catch them without further incident," she said.

"We certainly don't want to put our Canadian residents at risk to do that. We continue to ask people to be extra vigilant and to take proper precautions when you are in any area of Canada.

"If you have plans to travel somewhere, make sure that somebody is aware of what your plans are and communicate the plans out and make them known if those plans change."

McLeod and Schmegelsky are lifelong friends who, according to Schmegelsky's father, are "good kids".

In an interview yesterday, Al Schmegelsky described the pair as "best friends" who met in primary school.

He said his son and McLeod were disappointed with a recent job at Walmart — their first jobs since leaving high school — so they decided to head off in search of something better up north.

"They're just kids on an adventure. They're good boys," Al Schmegelsky said.

He admitted to having gifted his son an Airsoft replica gun for Christmas at the boy's request.

The happy couple had been planning their roadtrip for months. Photo / AP

He said Bryer had told him he and Kam had been "training in war" in the woods for more than two years and were masters of camouflage.

"My son he's like, they're huge into video games — all kids are — and two Christmases ago he asked me for an Airsoft gun, which is a replica gun, right?" Schmegelsky told CHEK News.

"So he was telling me: 'well me and the fellas, we like to go in the woods and play war' right?"

"So knowing that the both of them are totally into that, if there was any threat, they would have done what they've actually trained themselves to do and they would have camouflaged themselves in the woods."

Fowler and Deese were on the trip of a lifetime to Alaska when their blue Chevrolet van broke down on the side of Highway 97, 20km south of Liard River Hot Springs on July 15.

Passers-by asked the couple if they needed help by Fowler insisted he could fix the van himself.

Police said the couple had been victims of gun violence and their bodies — left in a ditch by the van — were "unrecognisable".