and journalist julian ryle is at yokohama bay and following developments he told us a little earlier why the japanese government felt it was necessary to put diamond princess in quarantine. you can see oklahoma behind me that's about 3 or 4 kilometers distant where i am i mean a residential district overlooking the ports but the japanese authorities are saying i just want to keep this out they have had 20 cases confirmed in japan's fall but they're very concerned that if 3700 people got off the boat it's actually all of those might be carrying this disease and then they could have a bigger problem will move hands but it looks like we're going to have to go through the entire book from stem to stern very very carefully and check every individual may not want to tell you a couple has done and of course often done we have to wait for the results of these tests to come through to be confirmed and of course the boat and cross to be cleaned whoso from stem to stern is going to be alone i'm kind staking process and that was julian ryle there reporting from yokohama in japan like many people