EDMONTON - RCMP say law enforcement officials on both sides of the Canada-U.S. border are on "high alert" for an escaped Arizona inmate and his suspected accomplice.

The fresh warning follows word that federal authorities south of the border appear baffled as to the whereabouts of John McCluskey and Casslyn Welch.

The search for the couple abruptly turned from Montana to Arkansas on Wednesday when a pair matching their description robbed a beauty salon in the town of Gentry.

However, the owner of the salon was shown pictures of the fugitives and is certain they were not the couple who robbed her business.

RCMP issued fresh news releases Thursday across Western Canada asking for the public's help finding the pair.

Sgt. Tim Taniguchi says they may have crossed the border undetected.

"While there's no information to confirm that these two fugitives have entered Canada, their current whereabouts are unknown," Taniguchi said.

McCluskey was part of a prison break which happened in Arizona on July 30th. Police believe Welch helped with the escape.

Police warn the escapees are extremely dangerous. They and fellow escaped convict Tracy Province, who split from the group and was arrested in Wyoming on Sunday, also are suspects in the deaths of an Oklahoma couple whose burned bodies were discovered last week in eastern New Mexico.

RCMP have moved their helicopter to the Alberta-U.S. border in case it's needed in the manhunt. Mounties said earlier this week that they were checking out reports from the public that McCluskey and Welch were sighted in Canada, but so far nothing has panned out.

The RCMP news releases Thursday said: "Law enforcement on both sides of the border are on high alert."

"It's simply meaning that we are aware of the information and the border patrols from both countries are aware of the two fugitives and are aware that they may or may not have crossed the border," Taniguchi explained.