Police issued a warning Monday for the public to be on the lookout for a high-risk offender who has just been released into the Calgary area.

Derek Ross Calf-Child, 46, has a lengthy criminal record that includes sexual assault, aggravated assault, and weapons possession.

Police said he has a history of sexually assaulting girls and women.

His most recent conviction involved an attack on a woman on the University of Calgary campus.

In November 2007, he stalked a 19-year-old woman from a downtown C-Train station to the university station before attacking her. He repeatedly punched her in the face while trying to sexually assault her.

He was eventually tackled and restrained by a security guard and a university professor who heard the woman's screams for help.

He was released after serving a 56-month prison sentence, including time-served, for sexual assault causing bodily harm.

Police said he would be monitored under their high-risk offender program.

Calf-Child is described as aboriginal, five feet, six inches tall, weighing 170 pounds and having brown eyes, a dark complexion and grey-black hair.