Two young men previously thought to be missing are now suspects in the double homicides of an American woman and her Australian boyfriend, police in Canada announced Tuesday. The suspects are also linked to the death of a man found in northern British Columbia.

The suspects were identified as Kam McLeod, 19, and Bryer Schmegelsky, 18. Police consider them dangerous and warned the public not to approach them but to instead call 911 immediately.

Police describe McLeod as having dark brown hair and brown eyes and Schmegelsky as having sandy-brown hair. They are both 6-foot-4 and about 169 pounds. Authorities said the pair were spotted in northern Saskatchewan and were seen driving a gray 2011 Toyota Rav4.

The Royal Mounted Police had been investigating Schmegelsky's burning car south of Dease Lake when they found a body of an unidentified man about a mile from the car. It was located some 300 miles along remote highways where 24-year-old Chynna Deese, an American, and her 23-year-old Australian boyfriend Lucas Fowler were found fatally shot a week ago.

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The young couple was wrapping up a two-week-long road trip through northern British Columbia and were found dead near their broken-down van.

Stephen Fowler sent a desperate plea for information surrounding the deaths of his son Lucas, and Lucas' girlfriend, a North Carolina.

"Two young people, who had everything ahead of them, tragically murdered," Fowler said.

Newly released surveillance video showed the couple hugging at a gas station two days before their bodies were discovered. Police also released a sketch of a person they say was seen talking to Fowler.

Surveillance video shows Chynna Deese and Lucas Fowler hugging at a gas station two days before their bodies were discovered. CBS News

About 300 miles south in the same province several days later, police found a burning car belonging to the two missing teens. Police released a sketch of the victim, asking for help identifying him.

"It's unusual to have two major investigations undergoing of this nature in Northern BC at the same time," said Janelle Shoihet of the Royal Canadian Mounted Police. "So we recognize that there is a possibility that these could be linked."

"48 Hours" has previously reported on a notorious remote stretch of road near these crimes dubbed the "Highway of Tears." In the last 40 years, at least 18 women have disappeared or been found murdered along it.

As authorities investigate whether any of these new cases might be related, the victims' friends and family want answers.

"He was such a friendly guy who was kind to people he didn't know, like it's surreal," said one of Fowler's friends.

Fowler's father is a police officer in Australia, and he has two colleagues with him in Canada. Police haven't determined the cause of death of the man found near the missing teens' car.

–Peter Martinez and Nikki Battiste contributed to this report.