A South Korean report said North Korea has beefed up its defense systems along the border with new rocket launchers capable of hitting targets beyond Seoul.
Yonhap news agency said new multiple rocket stations had been deployed to replace the older 240mm guns.
The new multiple rocket launchers has a maximum range of 70 kilometers (42 miles) and could reach beyond the South Korean capital, Yonhap quoted an unnamed government official as saying.
The South’s defense ministry has yet to comment on the report, which came amid an apparent lull in tensions on the Korean peninsula, AFP reports.
Pyongyang has long threatened to strike Seoul in past provocations. North Korea has 5,100 multiple rocket launchers, according to military data, which pose a serious security threat to South Korea.
In 2010, North Korea shelled the Yeonpyeong island near the disputed Yellow Sea border, killing four people in an unprecedented attack.
North Korean leader Kim Jong-Un in recent months has unleashed a barrage of nuclear rhetoric against South Korea, Japan and the US in the last months following sanctions on the regime for its nuclear programs.