cnn's diana magnay is joining us from tokyo right now. diana, what happened? >> reporter: hi, wolf.ell, the city of yokahoma accidentally sent out a tweet -- or the crisis agency did saying that north korea had already launched its missile. that tweet stayed up for 20 minutes, sent out to the agency's 42,000 followers. until they realized it was a mistake. apparently it was human error. but obviously very embarrassing for that particular official who sent it out. very embarrassing for the city, too, at a time at least of partially heightened tensions in this country, wolf. >> we've seen the patriot air defense missile batteries in downtown tokyo, if you will, diana. how worried are people there when they see these kinds of missiles, these batteries right in the heart of their city? >> reporter: well, they've seen them before. they've heard this kind of rhetoric coming out of north korea before. it's a bit like what kyung lah was telling us earlier. they've been here before. the thing is, they're a bit worried about kim jong-un as opposed to his father who was more of a known entity.

cnn's diana magnay is joining us from tokyo right now. diana, what happened? >> reporter: hi, wolf. city of yokahoma accidentally sent out a tweet -- or the crisis agency did saying that north korea had already launched its missile. that tweet stayed up for 20 minutes, sent out to the agency's 42,000 followers. until they realized it was a mistake. apparently it was human error. but obviously very embarrassing for that particular official who sent it out. very embarrassing for the city, too, at a time at least of partially heightened tensions in this country, wolf. >> we've seen the patriot air defense missile batteries in downtown tokyo, if you will, diana. how worried are people there when they see these kinds of missiles, these batteries right in the heart of their city? >> reporter: well, they've seen them before. they've heard this kind of rhetoric coming out of north korea before. it's a bit like what kyung lah was telling us earlier. they've been here before. the thing is, they're a bit worried about kim jong-un as opposed to his father who was more of a known entity. the mes

cnn's diana magnay is joining us from tokyo right now. diana, what happened? >> reporter: hi, wolf.k a home a accidently sent out a tweet saying north korea had already launched its missile. that tweet stayed up for 20 minutes, sent out to the agency's 42,000 followers. until they realized it was a mistake. apparently it was human error. but obviously very embarrassing for that particular official who sent it out. very embarrassing for the city, too, at a time at least of partially heightened tensions in this country, wolf. >> we've seen the patriot air defense missile batteries in downtown tokyo, if you will, diana. how worried are people there when they see these kinds of missiles, these batteries right in the heart of their city? >> reporter: well, they've seen them before. they've heard this kind of rhetoric coming out of north korea before. it's a bit like what kyung lah was telling us earlier. the thing is, they're a bit worried about kim jong-un as opposed to his father who was more of a known entity. the message at least from the government is, this is all in hand, we're doi

diana magnay reporting.et's take a look at some possible scenarios where they might fire a mice siel, what kind of response that would trigger from cnn's allies. what are you guys seeing? >> wolf, we've been gaming all afternoon. north korea, here, south korea here. let's say north korea did launch a missile and it went out over here and into the sea, what happens? >> there will be a tracking. the telemetry of that will be tracked. we'll identify where the launch is, what the arc is. >> we would know within seconds? >> instantaneously we would pick this up by sea, ground, air, space. this integrated target system. the japanese have an aegis system. >> if it went out there and it was not headed towards any target. it went to sea, as north korea said, would there be any response? >> there would be no kinetic response. we would not fire back. if we knew it was going to land harmlessly, we would collect intelligence. >> let's look at another scenario. let's say that north korea with a missile or artillery starte

. >> okay, diana magnay reporting from tokyo, thank you. >>> north korea is holding its hard line. just today it rejected a request by the south for dialogue, this as pyongyang gears up to celebrate the country's most important holiday. april 15th is the birthday of north korea's late founder kim il-sung. his grandson, kim jong-un, is supreme leader. many wonder if he'll use his grandfather's birthday to make good on his explosive rhetoric. >> kim jong-un has not been seen now in two weeks. the rhetoric has cooled. no one expects the north to embrace this dialogue with the south immediately. for now, it appears north is willing to simply change the subject. north korea began marking the birthday, the day of the sun as they call it for founding father kim il-sung. sitting at attention workers party loyalists faced a massive portrait of their great leader and listened to glowing recollections of his rule. no one smiled after all he has been dead for almost 20 years, but everyone applauded. off camera even the rhetoric aimed at pyongyang's critics was relatively muted. the puppet forc

our coverage of the korean crisis continues now with diana magnay. tell us more about the preparations. >> hi, john. actually, the missiles behind me, two patriot missile batteries that you can see there were deployed overnight at the ministry of defense in the heart of central tokyo. residents waking up and seeing these war machines where normally they see a baseball park. but this isn't the first time that they've seen that, john. there have been patriot missiles deployed in this spot and around tokyo three times since 2009. and that's every time that north korea has announced it will launch a satellite. so people are getting used to it to a certain extent. and these deployments come in conjunction also with war ships, destroyers being moved into the sea of japan. they also have a missile interception system onboard. i was talking to a security analyst earlier. he said, you know, even though pyongyang is just 800 miles from tokyo, if these systems work and all the tests would suggest that they're pretty effective, then they should keep the japanese