Japanese telecommunications carrier KDDI has apologized over a massive wildfire that broke out in a Mongolian nature reserve earlier this month, NHK World reported.

Mongolia’s state-run Montsame News Agency reported that the blaze started in the Numrug Strictly Protected Area in the eastern province of Dornod on October 8 and spread to grassland. KDDI has not disclosed details about the fire, but said Mobicom executives, including its Japanese CEO, entered the nature reserve by vehicle to conduct a communications network test.