Authorities say two B.C. teens, who were previously treated as missing persons, are now considered suspects in the deaths of three people in the northern part of the province.

RCMP said Tuesday that 19-year-old Kam McLeod and 18-year-old Bryer Schmegelsky are suspects in double homicide of a young couple found dead on a B.C. highway and the death of an unidentified man, whose body was found near the suspects' burning vehicle.

Authorities said the men have fled the province and were spotted in Saskatchewan, BC RCMP Sgt. Janelle Shoihet said.

"We believe that they're likely continuing to travel," she said.

"Though we don't have a possible destination, they were last seen driving a grey 2011 Toyota Rav-4."

Later, the Manitoba RCMP posted on Twitter that they had reason to believe the suspects were heading further east.

Shortly before 3 p.m., they wrote that they believed McLeod and Schmegelsky had been in the Gillam area "recently."

Gillam is a town on the Nelson River located about 300 kilometres northeast of Thompson, Man.

Mounties have asked anyone who sees them to call 911.

"Consider them dangerous. Do not approach. Take no action, and call immediately," Shoihet said earlier in the day.

Both are about 6'4" and 170 pounds. McLeod has dark brown hair, brown eyes and facial hair, while Schmegelsky has been described only as having sandy brown hair.

Police released new photos of McLeod and Schmegelsky as part of a public alert.

It's possible they may have made efforts to alter their appearance, the RCMP said, and they may have switched to a different vehicle.

"This investigation is very complex and ever-evolving. Investigators continue to follow up on tips, and reviewing the physical and digital evidence collected, and sharing information," Shoihet said.

The men have not been in touch with family or friends for a few days, police said previously.

The RCMP is investigating their alleged role in the double homicide of Australian Lucas Fowler and American Chynna Deese, and the death of an unidentified man found near a burning pickup truck. Their bodies were found in a span of four days on remote stretches of two B.C. highways.

Efforts continue to contact a man who may have interacted with Fowler and Deese before they were fatally shot. They are not calling the man shown in a sketch provided Monday a suspect in the case.

The couple's bodies were found on Highway 97 on July 15, near the blue 1986 Chevy van they'd been using for a road trip.

The teens' truck was found on Highway 37, about 460 kilometres away. The body of the unidentified man was on a highway pullout about two kilometres from the truck.

On Tuesday, RCMP did not provide further information on the man or his cause of death, and said they're still hoping the public will help identify him.

"We're not going into the specifics with respect to how that man died, we can just tell you that Kam and Byrer are wanted in relation to that man's death," she said.

She would not call his death a homicide or murder.

"The manner in which he died is not important at this point. What we want you to know is that we want the public and (the media), everybody who sees this today, to help us to locate Kam and Bryer," she said.

Shoihet wouldn't explain how the RCMP linked McLeod and Schmegelsky to both cases, saying only that they received new information.

"We have to make sure the integrity of our investigation is upheld," Shoihet said.


Do you know what happened? Plea for info

At the news conference more than a week after the first bodies were found, the RCMP also issued a plea to the public, asking anyone with information to contact them.

Specifically, they're asking for help to find the suspects, but they've also asked for witnesses and dash cam video. They've also released two sketches – one of the deceased found near the truck, and the other of the man who may have spoken to Deese and Fowler – and are looking for the public's help to identify both.

Shoihet said tips from the public have already helped move their investigation forward.

"We had no information as to Kam and Bryer's whereabouts. And because we made the appeal yesterday, we now have new information where we've confirmed that they were seen in northern British Columbia," she said.

"We've been able to confirm that information within the last 24 hours, and I have been receiving new information, honestly, before I just stepped up on this stage."

Tips can be left with the RCMP at 1-877-543-4822, or 778-290-5291. Information can also be provided anonymously through Crime Stoppers.

Other cases not believed to be related

Before Mounties made the announcement about the missing teens, Shoihet addressed two other cases that have been cause for speculation online.

In an email to CTV News Tuesday morning, she said two missing Surrey, B.C. men are not thought to be tied to the northern B.C. deaths. 

Richard Scurr and Ryan Provencher, both in their late 30s, were last seen in Surrey on July 17, and haven't been heard from since. Concerns were elevated when their white Jeep Cherokee was discovered in B.C.'s Southern Interior. It was empty at the time.

But the RCMP said they've confirmed their disappearance is not connected to the deaths last week.

The RCMP was also asked about a man wanted for murder in Texas, who is believed to have crossed the border into Manitoba late last month. 

Mounties said last week Derek Whisenand is believed to have entered Manitoba near Winkler, and travelled on to Winnipeg. He may have headed east, they said.

Shoihet told CTV Tuesday that a number of sources have provided information and it's been passed on to investigators, but that she did not believe he was being looked at in relation to the other cases.

Interactive map: 3 deaths in B.C.'s north