Safety concerns are mounting among guards at Stony Mountain Institution, just north of Winnipeg.

CBC News has learned more about a lockdown and search at the federal prison this past summer, with documents showing that officers seized numerous jail-made weapons and drugs.

The documents show correctional officers seized 17 homemade stabbing weapons — known as shanks — during the lockdown, which began on July 19 and took place over six days.

Kevin Grabowsky, the Prairie region president of the Union of Canadian Correctional Officers (UCCO), says that number is higher than normal.

He says safety at Stony is getting worse, and guards are concerned.

"Inmates are being more creative. They're making more weapons. We're finding more weapons all the time," he said.

"Double-bunking leads to problems; gangs lead to more problems, where inmates are … arming up more and more," he added. "People come to the backyards, up to the jail, and can throw stuff over."

A Stony Mountain official says security measures are in place and there's only so much they can do.

"We can't take everything from them; they live here," the official said.

'Ongoing concern' worldwide

Guy Langlois, an assistant warden at Stony Mountain, told CBC News in an email that the seized weapons have since been destroyed.

"The prevention and control of violence is an ongoing concern of correctional systems worldwide," he said.

He added that the Correctional Service of Canada, or CSC, "continues to work diligently towards ensuring the safety and security of our institutions."

A spokesperson for federal Public Safety Minister Vic Toews told CBC News that the CSC believes that double-bunking has "a minimal impact on the rates of violence in prisons."

In an email, the spokesperson said a recent analysis by the CSC found that double-bunked prisoners involved in violent incidents represented only one per cent of the total number of prisoners in the Prairies last year.

Growth in prison populations has been only 25 per cent of what the CSC had predicted, "and far below what critics are claiming," the minister's office said.

"Double-bunking is a completely normal practice used in many western countries," Toews's spokesperson said in the email.

"Rather than engaging in political stunts and spreading misinformation, UCCO [the Union of Canadian Correctional Officers] should work with our government to help keep our streets and communities safe."

But Grabowsky questioned the numbers cited by Toews's office, arguing that there is still a growing inmate population and prisons are having to do less with programming.