North Korea is deploying improved artilleries with a longer range at its front-line military units, a government source said Sunday, indicating that they will pose a greater threat to South Korea‘s capital areas.

North Korea’s military is replacing 107-millimeter-caliber multiple rocket launchers deployed at its front-line artillery units with the improved 240-mm-caliber multiple rocket launchers, the source said.

North Korea is believed to have deployed multiple rocket launchers with three different caliber sizes -- 107mm, 122mm, 240mm -- on the border.

The 240-mm-caliber launcher has a range of 60 kilometers, but the improved version, now replacing the 107-mm-caliber ones, increases the range by up to 10km, according to the source.

“We are detecting signs that the North is deploying the improved 240-mm-caliber multiple rocket launchers, and the signs are showing up at some western and eastern front-line military units,” the source said.

The North Korean military has been developing the new version in order to increase its target range and has recently succeeded in producing it for actual use, according to the source.

The new artilleries pose increased military threats to areas south of South Korea‘s capital region, which is near the border with the North, the source added.

A U.S. Department of Defense report submitted to Congress last month showed that the North has a total of 5,100 multiple rocket launchers. (Yonhap News)