Authorities are warning a convict who escaped from a southern Alberta medium-security prison may have fled north.

Shawn Thomas Evjen, 46, disappeared from the Bowden Institution around 9 p.m. Monday.

“When he left, we were aware of how, and now we’re doing a review of our security measures,” Correctional Services spokesman Rick Mollan said.

The prison was locked down, and a canine team and helicopter scoured the area, but found no signs of the missing criminal.

Evjen, who has been in prison since July 1985, was serving out time for offences including robbery, use of a firearm and assaulting a peace officer.

Officials are warning the public they consider Evjen armed and dangerous, given his history and high risk to re-offend.

He stands at five-feet, seven-inches tall and weighs 166 pounds with red hair and blue eyes. He has a skull and dragon tattoo on his right forearm, and has tattoos of women, dragons, a bear and a warrior on his chest and back.

Police are urging anyone with information about Evjen, or anyone who spots him not to approach him and to instead call RCMP.