Inmates and guards travelling in an Alberta sheriff's van escaped without injury after the vehicle was involved in a fiery crash Thursday morning.

Police first heard about the crash -- on the Queen Elizabeth II highway, south of Edmonton -- at about 8 a.m. local time.

The prisoner transport van, carrying nine inmates and two guards, rear-ended a truck that had stopped to avoid a previous collision in the southbound lanes. The local RCMP said four vehicles in total were involved in the two crashes, near highway exit 525 in Leduc County.

Police said the guards were able to safely remove the passengers from the van, which quickly caught fire and became engulfed in flames.

The charred wreck, including a crumpled hood and badly-burned driver's side door, could be seen sitting on the highway throughout the morning.

"These guys are lucky -- I think very lucky today -- just by looking at this van," Leduc Integrated Traffic Services Cpl. Alex Dasilva told CTV Edmonton.

The van's occupants were taken to Leduc Hospital for examination, but no serious injuries are being reported. The accident remains under police investigation.