The fire broke out on Tuesday in the commune of Bois-de-Champ, at a time when eastern France has been suffering from a lack of rain for several weeks and strong winds.
Since Tuesday evening, a helicopter has carried out around fifty drops of 3.5 tonnes of water.
State authorities are calling for "the utmost vigilance throughout the department", given the very dry weather conditions and the fact rain is not expected for several days.
On Wednesday, 27 Départements were placed on yellow alert over the risk of fires by Météo France.
