The teenagers also liked to play video games that simulated war and involved hunting and camouflage.

On Tuesday the Royal Canadian Mounted Police named the teenagers as suspects in a murderous rampage across remote northern British Columbia that included the highway shooting murders of Australian tourist Lucas Fowler and his US girlfriend Chynna Deese.

McLeod, 19, and Schmegelsky, 18, from Port Alberni, near Vancouver, are also suspects in the death of a yet-to-be identified middle-aged man found lying near where the teenager's Dodge pick-up truck was set alight on Friday.

A massive manhunt is underway, with the teenagers driving thousands of kilometres east across remote northern Canada.

On Tuesday morning the RCMP reported they were spotted driving a grey 2011 Toyota RAV4 more than 2,000km away from BC in northern Saskatchewan, a province in central Canada.

Just hours later the RMCP issued an alert to residents of Manitoba, the province to the east of Saskatchewan, to say "we have reasons to believe they were recently in the Gillam area" of Manitoba.

"If you spot them - take no actions - do not approach - call 911 or your local police immediately," the RCMP alert warns.

The teenage duo is considered so dangerous the RCMP said a decision to call Tuesday's press conference and go public with their concerns was "unprecedented".

"If you spot Bryer or Kam consider them dangerous," Royal Canadian Mounted Police Sergeant Janelle Shoihet told reporters.

"Do not approach, do not take action and call 911 immediately."

McLeod and Schmegelsky were originally deemed missing, but that took a dramatic turn at the press conference.

The teens were first loosely connected to the murder of Mr Fowler and Ms Deese on Friday when their Dodge was found burning on a highway and a man's body was found 2kms away.

This carnage took place near Dease Lake, 470km away from the Alaska Highway location near Liard Hot Springs where Mr Fowler and Ms Deese were found shot dead in a ditch.

The distance between the two locations initially had the RCMP reluctant to link the bodies.

McLeod and Schmegelsky, who had been friends since elementary school and had worked at Walmart to save for a trip north to find work at Whitehorse in the Yukon Territory, are now considered armed and dangerous.

"Given these latest developments Cameron and Bryer are no longer considered missing," Sgt Shoihet said.

"The RCMP are now considering Cam McLeod and Bryer Schmegelsky as suspects in the Dease Lake suspicious death and the double homicide of Lucas Fowler and Chynna Deese."

The RCMP released new, recent security camera photos of the teens in northern Saskatchewan.

Mr Fowler, 23, the son of a senior NSW police officer, and Ms Deese, 24, from North Carolina, were stranded on the highway after their blue 1986 Chevrolet van broke down on the afternoon of July 14.

Mr Fowler and Ms Deese met two years ago backpacking in Croatia, fell in love and were on a road trip through Canada when they were murdered.

Schmegelsky's family members have offered positive descriptions of the teenagers.

His grandmother, Carol Starkey, told the Times Colonist newspaper Schmegelsky "was a great kid".

His father, Alan Schmegelsky, said his son and McLeod were "best friends who did everything together" and liked to play video games that simulate war and involve hunting and camouflage.

"They even got jobs together at Walmart," Mr Schmegelsky said.

"They were just out on an adventure."

Australian Associated Press