May 23, 2013 09:17 South Korean military authorities are trying to figure out how to respond to a three-day test of North Korea's new multiple rocket launchers. The new MRLs are deemed to be more formidable and have a longer range than the 240-mm MRLs currently aimed at the Seoul area. With an estimated range of 180 to 200 km, the new MRLs could strike South Korean military headquarters at Gyeryongdae in South Chungcheong Province and U.S. bases in Pyeongtaek and Osan, both in Gyeonggi Province. The South Korean military is especially worried that they could be set up in caves in the frontline area near the demilitarized zone.