ben wedeman live in jerusalem. thanks, ben. >>> the man leading the search for flight 370, they say they're looking at all of the underwater signals. they're responding to a wall street journal report casting doubt on two of the four pings. some of the australian pings thinks the frequency of two of the signals is too low to be from the flight's signature nals. at this point it is too early to discount the signals. the four signals taken together constitute the most promising news we have. >>> for more proof of how dangerous the middle east are, security concerns in yemen are so dangerous the u.s. embassy plans to stay closed for another two weeks. >> with tense battles between al qaeda and security forces intensifying throughout yemen, cnn has learned that it's become so critical the embassy will be shut down for at least two more weeks. an extraordinarily long time and quite rare showcasing how dangerous the country's situation has become. >> we said we would open it when it's practical. we continue to evaluate it