Winkler firefighters joined forces with the Walhalla Fire Department late Wednesday night to battle a grass fire raging on the US border.

Both departments worked for four hours to contain the blaze.

Winkler Fire Chief Richard Paetzold explains the fire started on the Canadian side, though local firefighters chased it across the border into North Dakota.

He says their main objective was to protect corn crops on either side of the bush fire.

Paetzold notes they're still investigating how the fire started.

RCMP are also involved in the investigation.