North Korea threatens to fire at loudspeakers

GYERYONGDAE, South Korea, Sept. 29 (UPI) -- South Korea says it is boosting its military presence at the demilitarized zone to thwart a possible assault by North Korea on propaganda loudspeakers.

Yonhap News Agency said South Korea has resumed its anti-Pyongyang propaganda operations after a six-year moratorium but has yet to resume using the loudspeakers. North Korea has threatened to fire at the loudspeakers if they are returned to use.

South Korea says it deployed unmanned surveillance aircraft equipped with infrared cameras to the border, as well as more anti-tank missiles and anti-aircraft guns .

Yonhap said tensions between North and South Korea remain high after last year's sinking of a South Korean warship and North Korea's shelling of Yeonpyeong Island.