Mid-Canterbury farmers have been warned to be extra-vigilant as police investigate several cases of suspected arson on farms in the Ashburton area.
Four fires were lit in the early hours of Saturday morning, three in straw bales and one in a hay barn that also housed machinery.
The chair of Federated Farmers' Mid-Canterbury grain and seed group, David Clark, says it's an act of stupidity and even more dangerous at this time of year when harvesting is under way.
