emergency situation briefing. ian williams is with us this morning. >> this is one of the shelters, a pretty heavy bomb-proof door, now after the exchange of artillery last night, about 60 people in local villages were ordered here around 40 of them staying overnight. some did manage to return home today, but they have been told to come back here with tensions rising this evening across the border area. north korea sits just over the hills behind me. there are lots of reasons why this is a pretty scary border area, but what's most rattled kim jong-un, 11 vast installations of loud speakers which over the last few days have begun broadcasting propaganda into the north. he doesn't like that. he's called that an act of war. now, the reason the south restarted this propaganda operation after a break of 11 years is a mine attack which badly injured two south korean soldiers just a few days ago.