The RCMP in British Columbia have issued a warning that two escaped American convicts and the woman suspected of helping them break free may be headed for the Canadian border.

"The public is advised that if you see any of these individuals please consider them armed and dangerous and do not approach them," the RCMP said in a release Sunday.

The men, Tracy Province and John McCluskey, escaped from a private medium-security Arizona prison on July 30.

According to the U.S. Marshals Service, information gathered in the last two days indicates the pair and their alleged accomplice Casslyn Welch may be hiding in an area of Yellowstone National Park that spans the Montana-Wyoming border.

According to the supervisory deputy with the U.S. Marshals Service in Phoenix, the three don't appear to be expert campers.

"From the start, we believed these individuals would be staying at campgrounds and truck stops and other places like that. This keeps to that pattern," Thomas Henman said Sunday.

Authorities also said Province, 42, is believed to have separated from 45-year-old McCluskey and his cousin and fiancee Welch, 44.

The men have been on the run for nine days, but the hunt intensified Saturday after forensic evidence linked at least one of the escapees to the killings of an Oklahoma couple in eastern New Mexico.

Linda and Gary Haas' burned skeletal remains were discovered Wednesday morning in a charred camper on a ranch in Santa Rosa. The couple's truck was found 160 kilometres west in Albuquerque.

Given the double-homicide, both Henman and New Mexico State Police spokesperson Lt. Robert Shilling said the search had become "urgent."

"The public needs to be vigilant more than anything. Not alarmed, not scared, but vigilant," Shilling urged.

Province, McCluskey and a third inmate Daniel Reswick escaped from the Arizona State Prison near Kingman after Welch allegedly threw wire cutters over the perimeter fence.

The inmates are then believed to have kidnapped two semi-truck drivers at gunpoint, eventually leaving the drivers unharmed at a truckstop.

Renwick, who had been serving a 22-year sentence for second-degree murder, was recaptured in Colorado the day after the escape following a shootout with police.

Province was serving a life sentence for murder and robbery, while McCluskey was serving a 15-year prison term for attempted second-degree murder, aggravated assault and discharge of a firearm.

McCluskey's mother, 68-year-old Claudia Washburn, was arrested Saturday in Arizona. Henman said she is being charged with conspiracy to commit escape, hindering prosecution, and facilitation to commit escape.

McCluskey is described as 6-foot-1 and 200 pounds. Province is 6-foot-2 and 180 pounds. Welch is 5-foot-3, and 135 pounds.

With files from CTV's Joy Malbon, The Canadian Press and The Associated Press