SMOKY LAKE, Alta. - RCMP in Smoky Lake, Alta., say 11 vehicles have collided on Highway 28 east of the community.

They say several people have been taken to hospital with non-life-threatening injuries, adding most of the occupants of the vehicles escaped injury.

RCMP say the area of the collision was experiencing thick smoke and foggy conditions at the time and visibility was greatly reduced.

Fire departments and EMS crews from Smoky Lake, Vilna and Waskatenau responded to the incident.

RCMP say there were frightening moments for rescue crews working at the initial collision, which involved seven vehicles.

Mounties say three vehicles including a rescue vehicle were knocked into the crash scene by a fourth vehicle approaching from behind.

The highway was closed to traffic for several hours to allow for crews to clear up the debris, but has since reopened.

Earlier on HuffPost:

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  • This image made from video provided by KABC-TV shows fire officials working on a freeway pileup in northern Los Angeles County involving at least 19 vehicles that has injured at least 15 people, two of them critically. Los Angeles County fire Capt. Mark Savage says the vehicles, including one or two big-rig trucks, tangled early Tuesday morning on the southbound side of State Route 14 midway between the high desert Antelope Valley and the Los Angeles Basin. (AP Photo/KABC-TV)

  • Firefighting paramedics remove an injured motorist after an accident, Tuesday, June 26, 2012 at the site of a freeway pileup in northern Los Angeles County involving at least 19 vehicles and left at least 15 people injured, two of them critically. (AP Photo/Rick McClure)

  • Firefighting paramedics remove an injured motorist after an accident Tuesday June 26, 2012 at the site of a freeway pileup in northern Los Angeles County. (AP Photo/Rick McClure)

  • Firefighting paramedics assist an injured motorist after an accident Tuesday June 26, 2012 at the site of a freeway pileup in northern Los Angeles County. (AP Photo/Rick McClure)