YEONCHEON (Yonhap News) -- A Korean worker was slightly injured Saturday after an unidentified explosive device went off near the heavily fortified border with North Korea, military officials said.

The accident happened around 9:40 a.m. when the 40-year-old, identified only by his family name Cho, was overseeing excavation work near a military base.

Cho is currently being treated for debris injuries at a nearby hospital, said a military official at the hospital. Cho is conscious and his condition is not life-threatening.

Another official said a mine may have exploded during the excavation work, adding that an investigation is under way to determine the exact cause of the accident.

The two officials did not give any further details and asked not to be identified as they were not authorized to speak to the media.

(Yonhap News)