One of North Korea’s trash balloons caused a fire at a South Korean warehouse on Sunday.

According to police and fire authorities, the balloon fell on the roof of the warehouse in Paju, Gyeonggi Province, around 2 p.m., and the roof caught fire shortly after that.

The fire was extinguished after three hours, having burned 330 square meters of the roof and caused damage amounting to 87-point-29 million won, or over 65-thousand U.S. dollars.

A preliminary investigation pointed to a detonator attached to the balloon.

North Korea has recently begun attaching detonators to balloons, timed to explode to disperse the trash.