North Korea is known to have added over the past year some 200 multi-rocket launchers pointed at South Korea's capital area near the military border amid heightened tension between the two sides.

A South Korean official says South Korean and U.S. intelligence have detected deployment of 53-hundred launchers on the inter-Korean border.

The 240-millimeter multi-rocket launcher can shoot rounds every 35 minutes and has a range of 60 kilometers, putting Seoul and vicinity within striking distance.

Pyongyang is known to have added 21-hundred field artillery guns and 300 tanks to its arsenal over the past year.

The Defense Ministry in Seoul will reflect these movements in its 2010 defense white paper set for release early next month.