Protesters denounce North Korea in front of the Defense Ministry, Wednesday, Nov. 24, 2010 in Seoul, South Korea. South Korea's troops were on high alert Wednesday as their government exchanged threats with rival North Korea following a frightening military skirmish that ratcheted tensions on the peninsula to new extremes. (AP Photo/Wally Santana)

Photo by: Wally Santana

Protesters denounce North Korea in front of the Defense Ministry, Wednesday, Nov. 24, 2010 in Seoul, South Korea. South Korea's troops were on high alert Wednesday as their government exchanged threats with rival North Korea following a frightening military skirmish that ratcheted tensions on the peninsula to new extremes. (AP Photo/Wally Santana)