Ryan John Agecoutay (RCMP)Preston Clarence Buffalocalf (RCMP)Cody Dillon Keenatch (RCMP)James Joseph Pewean (RCMP)Daniel Richard Wolfe (RCMP)Saskatchewan's minister of public safety has ordered an investigation into why 15 hours passed before authorities alerted the public about a prison break by six inmates.

One of six escapees was caught a short time after fleeing the Regina Correctional Centre on Sunday night at about 10 p.m., but five were still on the loose Tuesday.

A Canada-wide warrant was issued for the five escaped inmates, described as "dangerous and possibly armed" at a Monday afternoon news conference where the public was first alerted about the incident.

With the Trans-Canada Highway nearby, police acknowledge that the inmates could have travelled far in the hours since their escape.

"We've got a pretty big country. They could be just about anywhere," said RCMP Sgt. Doug Coleman.

The five escapees are Ryan John Agecoutay, 25, Preston Clarence Buffalocalf, 22, Cody Dillon Keenatch, 19, James Joseph Pewean, 25, and Daniel Richard Wolfe, 32.

Sources told CBC News that the men escaped by pulling a vent off a wall, crawling into it and then kicking their way through an exterior brick wall. The brick wall did not have any reinforced concrete or rebar.

At least four of the men are awaiting trial for various violent offences. One is charged with two counts of murder and three face attempted murder charges in connection to shootings during a violent home invasion last year.

Corrections, Public Safety and Policing Minister Darryl Hickie first learned of the breakout earlier than the public, about 7 a.m. CT. The public was not alerted for another six hours.

"I believe that in this case, it sure would seem to me that the most critical thing to do would have been to inform the public at first time [in the morning] to ensure that people were aware of this," Hickie said Monday.

Police defended the delay, saying it took time to gather information, co-ordinate a police response and ensure they were making the right names public.

"We have to always ensure people's rights are protected. So, that we do want to make sure we have the right people missing," said Coleman.

Hickie, a former corrections worker, said he understands officials have many urgent tasks following an escape, but public safety should be a priority.

In the past decade, the Regina Correctional Centre has experienced at least four other breakouts.

In 2003, five inmates broke out of the facility by digging a hole in the roof of an auditorium. Another incident saw two prisoners claw their way through a brick shower room wall.

Hickie said he wants to know why people escaped again from what should be a secure facility.

While previous escapes happened in the original jail built in 1913, the latest incident occurred in an addition completed in the 1960s.

A $40.7-million construction project to replace the 1913 portion of the facility is currently underway, with the new building expected to be completed in the next few weeks. The addition is not slated for replacement.