They say the teens are believed to still be in the Gillam area of the province where a burned-out vehicle the suspects were driving was located.
Royal Canadian Mounted Police Cpl. Julie Courchaine said authorities have corroborated the sightings of 19-year-old Kam McLeod and 18-year-old Bryer Schmegelsky.
She said the sightings were prior to Monday evening's discovery of the suspect's vehicle.
Courchaine said there have been no reports of stolen vehicles that could be attributed to the suspects and that is why authorities believe the men are still in the Gillam area.
She described the terrain there as unforgiving. "There's lots of dense bush, forest, swampy area, so it is very challenging," she said.
DISCOVERING THE VICTIMS
Gillam is more than 2,000 miles from northern British Columbia, where another burned vehicle, a camper truck, was found Friday, and the three victims were discovered.
The victims have been identified as American Chynna Deese, Australian Lucas Fowler, and Canadian Leonard Dyck.
Police found Dyck's body near a highway roughly a mile from the first burned-out vehicle on July 19.
That was about 300 miles from the spot along the Alaska Highway near Liard Hot Springs where Deese and Fowler were found shot dead days earlier.
Deese and Fowler were dating. Fowler, the 23-year-old son of a chief inspector with the New South Wales Police Department, was living in British Columbia, and Deese was visiting him.
Deese, a 24-year-old from Charlotte, North Carolina, was "the most beautiful person and most just warming infectious person," her brother British Deese told WSOC-TV. "She lit up every room she went in and she was just the glue to so many relationships."
The Royal Canadian Mounted Police released a video of the couple at a gas station about a day before the murder. In the video, Fowler fills the vehicle with gas while Deese cleans the windows. After, the young couple shares an embrace before going into the store.
How sad it is to see this hug of two young people in love. Police have released CCTV of Lucas Fowler and Chynna Deese filling up with petrol at Fort Nelson two days before their bodies were found shot dead on the Alaska Hwy in Canada. @10NewsFirstSyd pic.twitter.com/VMLVLsn2cG— Steve Hart (@SteveHart10News) July 23, 2019
Dyck, 64, was a college professor in Vancouver.
The separate discoveries of three bodies and burning cars have shaken rural northern British Columbia.
SUSPECT'S FATHER SPEAKS OUT
McLeod and Schmegelsky have been charged with second-degree murder in Dyck's death and are suspects in the couple's murder.
McLeod and Schmegelsky themselves had originally been considered missing persons and only became suspects in the case Tuesday.
Alan Schmegelsky said he believes his son is on a suicide mission and that the manhunt will end in his death.
"A normal child doesn't travel across the country killing people. A child in serious pain does," Alan Schmegelsky said.
He added, "I love you. I'm so sorry all of this had to happen. I'm so sorry that I couldn't rescue you."
The father, who is estranged from the teen's mother, explained that he didn't see his son between the ages of 8 and 16, and during that time the boy came under the mistaken belief that he had Russian heritage.
He said his son is a supporter of Russian President Vladimir Putin and U.S. President Donald Trump.
"I argued with him about that, in a friendly manner," the father said. "He liked strong speakers."
INVESTIGATING NAZI SYMBOLISM ONLINE
Police also said Thursday that they were investigating a photograph of Nazi paraphernalia allegedly sent online by one of the suspects.
Bryer Schmegelsky allegedly sent photographs of a swastika armband and a Hitler Youth knife to an online friend on the video-game network Steam, the Canada Globe and Mail reports.
Lisa Lucas, the mother of a different gamer, said her son used to play with Schmegelsky. She said her son saw "the Nazi symbol on one of his social media" accounts years ago and decided to stop playing with him.
Alan Schmegelsky said his son took him to an army surplus store about eight months ago in his small Vancouver Island hometown of Port Alberni, where his son was excited about the Nazi artifacts.
"I was disgusted and dragged him out," the father told Canadian Press. "My grandparents fled the Ukraine with three small children during the Second World War."
Alan Schmegelsky said he didn't believe that his son identified as a neo-Nazi, but that he did think the memorabilia was "cool."
Missing men connected to burning car now suspects after NC woman, Australian boyfriend murdered in Canada
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The ABC Owned Stations and ABC News contributed to this report.