By Greg Botelho and Holly Yan, CNN Mon December 19, 20111
Tearful reaction to Kim's death
STORY HIGHLIGHTS
- NEW: South avoiding "anything troublesome," a U.S.-based diplomat says
- NEW: The U.S. sees no sign of movement across the DMZ, general says
- Kim Jong Il died of a heart attack while on a train, KCNA says
- The ruling Workers' Party dubs his son Kim Jong Un "the great successor"
(CNN) -- Seoul put South Korean forces on high alert and Pyongyang urged an increase in its "military capability" as the death of North Korea's enigmatic leader Kim Jong Il spurred fresh security concerns in the tense region.
The 69-year-old "dear leader" of the reclusive communist state died of a heart attack on Saturday, state news outlets reported Monday. The ruling Worker's Party proclaimed his youngest son, Kim Jong Un, "the great successor," indicating he would assume his father's post.
