The president of the union representing Alberta’s striking jail guards says they are refusing to return to work, despite a labour board ruling that declared the strike illegal.

Guards at the Edmonton Remand Centre and another facility in Fort Saskatchewan are vowing to continue their strike until safety concerns are addressed, Guy Smith of the Alberta Union of Provincial Employees said.

Earlier Saturday, the Alberta labour board ruled the wildcat strike illegal and ordered staff at the two facilities to go back to work.

Guards from at least five other correctional facilities have also walked off the job since Friday to protest the suspension of a worker at the Edmonton Remand Centre who complained about safety issues at the newly-built facility.

Alberta's deputy premier Thomas Lukaszuk said Saturday that he was getting second-hand reports about inmates trashing the remand centre in the guards’ absence.

"It's heartbreaking that a brand-new $580 million facility that taxpayers have paid for is being trashed by inmates right now," Lukaszuk told reporters.

However, he stressed that no one was in danger inside or outside Alberta’s jails.

There were reports of inmates banging on the walls and, in some cases, smashing windows. Nurses at the remand centre feared for their safety and left the building, their union said.

Earlier in the day, authorities said that inmates were restricted to their cells and striking staff have been either replaced by municipal police or RCMP officers along with correctional supervisors.

While the labour board’s ruling applies to guards at the Edmonton Remand Centre and the Fort Saskatchewan facility, it isn’t clear what will happen at the other detention centres involved in the job action.

Clarke McChesney, chairman of The Alberta Union of Provincial Employees Local 003, said guards at the new remand centre brought forward a number of issues prior to the jail’s opening.

“We wanted to slow the process down,” McChesney told CTV News Channel on Saturday.

The AUPE claims that it had found five pages worth of design flaws after touring the sprawling facility, which will eventually hold up to 2,000 inmates.

The union also said it was not satisfied with some of the new procedures implemented at the mega-jail.

“The technology is really outstanding,” he said. “There are lots of really great things that are going to happen and a transition we’re very excited about being a part of, but we wanted it done in a safe manner.”

Inmates began moving into the north Edmonton centre on April 12.

McChesney said concerns were raised “months” before the opening.

“We lit that fuse months and months ago, about the concerns, and it boiled over (Friday),” he said.

When 70 employees who arrived for their shift Friday afternoon refused to enter the remand centre, officials placed the jail under lockdown.

The wildcat strike quickly spread to several other correctional facilities in the province by Saturday, including Peace River correctional centre, the Lethbridge correctional centre, the Fort Saskatchewan centre, the Calgary correctional centre, the Calgary remand centre and the Edmonton Young Offenders Centre.

Alberta’s Justice Minister Jonathan Denis called the wildcat strike “illegal job action.”

“Any threats to public safety are dealt with swiftly and seriously by this government,” Denis said in a statement, adding that contingency plans are in place to make sure the facilities continue to operate securely.

McChesney said the union will have to see some sort of positive dialogue with provincial authorities and “genuine” changes.

“So we don’t have to explain to our family members what happened at work when we weren’t taken care of,” he said.

With a report from CTV's Alberta Bureau Chief Janet Dirks and files from The Canadian Press