BERMAN: Happening now the Pentagon monitoring escalating tensions between North and South Korea. More than just tensions. The two countries exchanged fire. North Korea fired the first shot taking aim at a loudspeaker broadcasting anti-Pyongyang propaganda across the border. South Korea retaliated with 36 artillery shells. Want to bring in Kathy Novak, CNN's Kathy Novak, from Seoul. Kathy, we hear threats all the time. It's been some time since we've seen live fire between the two countries.</s>KATHY NOVAK, CNN CORRESPONDENT: Absolutely, and the tensions have been ramping up the last couple of weeks. South Korea's military on high alert and the president ordering it to sternly take action against North Korea's provocation. This is all happening as the United States is holding joint military drills with South Korea. We know Pyongyang threatened to attack the U.S. mainland over that. It's angry about the propaganda messages being broadcast through the loudspeaker that you referred to there. Now this is part of psychological warfare, something South Korea hasn't done in more than ten years and Pyongyang threatened to blow up the speakers. It threatened indiscriminate threats against South Korea and after this exchange of fire it issued an ultimatum. If South Korea does not stop the broadcasts by 5:00 p.m. on Saturday, Seoul time, North Korea will take military action.</s>BERMAN: Has South Korea responded to that? Do they continue to broadcast?</s>NOVAK: As far as we know, it is continuing to broadcast. And as we know the president chaired a meeting of the National Security Council ordering stern action against North Korea. Now these psychological warfare methods were taken in retaliation for land mines that South Korea was blaming on North Korea. Those badly injured two South Korean soldiers -- John?</s>BERMAN: All right. This tension showing no signs of abating. We'll have to watch it very closely. Kathy, thanks so much. And thank you all so much for joining us AT THIS HOUR. "Legal View" with Ashleigh Banfield starts after a quick break.
Shots Fired Between North, South Korea.