07/21/2015 10:01 EDT | Updated 07/21/2016 05:59 EDT

Burning truck, hay, grass, make drivers squint on southern Alberta highway

BROOKS, Alta. - Drivers had to deal with reduced visibility from smoke when a semi-trailer truck carrying hay bales caught fire on the Trans-Canada Highway in southern Alberta.

Police say a mechanical problem in the truck sparked the mid-afternoon Monday fire near Brooks, about 190 kilometres southeast of Calgary.

The flames spread to the 10-tonne load of bales and from there to nearby grass.

Motorists approaching the scene were forced to detour before the fire was eventually put out about four hours later.

No one was hurt. (CHQR)