Luxembourg’s fire brigade, the CGDIS, said on its Facebook page that it had a number of crews and equipment on the scene.
The fire service did not report the suspected cause of the fire, however Meteolux reported a temperature of nearly 40C and very low humidity around the time the fire was detected.
RTL's Luxembourg-language website reported that a fire department vehicle was engulfed by the flames and exploded, though no injuries were reported.
The smoke was visible from Sandweiler roundabout, one motorist told Delano.
UPDATE: Just after 4pm reports came in that the fire had spread through the forest towards Pulvermühle, and that the two filling stations down in the valley had been evacuated as a precaution.