(VOVworld) – South Korea has raised its military alert to the highest level at locations along the border where loudspeakers will resume propaganda broadcasts into North Korea on Friday, Yonhap news agency reported on Thursday.

The decision was made a day after North Korea announced successful testing of an H bomb. Yonhap quoted a defense official as saying that soldiers at 10 locations along the border are on high alert and more surveillance devices have been installed. The South Korean army has deployed more drones, anti-tank missiles, and counter-battery radars.