A bomb was detonated outside the office overnight on Thursday, causing damage to a door and part of a ceiling collapsed, Radio France Internationale reported.
"Le Foll!!" -- the surname of the Socialist agriculture minister -- was spray-painted on the building, as well as CAV, which stands for the Comite d'Action Viticole, or winemakers' action committee.
So far, no group has claimed responsibility for the attack.
Meanwhile, investigators are looking into whether militant winemakers are responsible for the attack, The Guardian, Britain, reported.
During the past several decades, winegrowers from southern France have staged guerrilla actions over low prices, unfair competition, foreign imports and what they see is as not enough government support. Such actions have included bombing the agriculture ministry buildings, hijacking foreign wine-tankers, vandalizing grocery stores, and dumping gallons of wine down the drain to express.