Two men, one a convicted killer, are on the loose Monday after escaping from William Head prison, southwest of Victoria.

The West Shore RCMP have deployed officers on the ground and in a police helicopter to search for the men.

Inmates James Lee Busch and Zachary Armitage escaped from the federal prison at 6:45 p.m. Sunday, according to the RCMP and a spokesperson for the Correctional Service of Canada.

The men were unaccounted for at the 11 p.m. roll call Sunday. The Correctional Service of Canada first reported the men missing on social media Monday morning.

Busch, 42, is serving an indeterminate sentence for second-degree murder and assault. He is also serving time for aggravated sexual assault, escape from lawful custody and other offences.

Busch pleaded guilty in July 2010 to killing a Saskatoon woman over a $20 piece of crack cocaine and throwing her body in a dumpster.

Documents obtained by CTV News in 2010 showed that at the time of his arrest, the National Parole Board considered Busch likely to reoffend after serving a seven-year term for aggravated sexual assault against a seven-year-old girl.   

The parole board was deeply concerned Busch had not completed sex offender or anger management treatment. He had been diagnosed with schizophrenia and would hear voices that told him to harm others, according to the documents. 

Busch is described as five feet nine inches tall, with a medium complexion, brown eyes and a shaved head, weighing 179 pounds. He has a skull tattoo on his left forearm, according to police.

Armitage, 30, is serving a nearly 14-year sentence for robbery, aggravated assault and other offences.

He is described as five feet 10 inches tall, with a fair complexion, brown eyes and black hair, weighing 170 pounds. He has a "No Love" tattoo with a crown on his right arm.

"We are working with police to locate the inmates as quickly as possible," the correctional service said.

Both men are considered dangerous and anyone who has information on the whereabouts of Busch or Armitage is asked to call 911 immediately.

"We take all escapes seriously and we learn from our escapes," assistant warden Tony Baldo told CTV News on Monday.

"I don't know at this point where the search grid is. They [RCMP] asked our security staff a number of questions, they provided answers to those questions and then they go from there as far as any leads they may have gleaned from that."

William Head Institution is a minimum-security prison that currently houses approximately 160 federal offenders in Metchosin.

The prison is surrounded on three sides by water, and several prisoners have either escaped or attempted to escape by swimming around a tall fence topped with razor wire, including two who died in 1993 and 1997.