COCHRANE, Alta. -- Alberta Fish and Wildlife says a quad rider and another rider on a motocross bike were attacked by a mother grizzly bear northwest of Cochrane.

The agency's enforcement division says in a Facebook post that the two riders were in an area known as the Ghost Public Land Use Zone on Saturday evening when they encountered two cubs.

The mother then attacked the riders, and the attack continued until one of the riders was able to pepper spray the bear.

The riders then got on the quad and rode for help.

One was seriously injured and was flown by helicopter to Calgary, while the other's injuries were minor.

Alberta Fish and Wildlife says it has now closed the area to the public.