(i) "The Chinese military issued a warning to a U.S. Air Force B-1 bomber flying in the East China Sea Wednesday morning amid escalating tensions in the region, two US officials told Fox News.
(ii) "American officials tell Fox News the bomber was flying in international airspace and continued on its mission---albeit without its wingman.
"Fox News has learned that two B-1 bombers were supposed to launch a patrol from Guam to the Korean Peninsula as part of training exercises with the South Koreans, hours after the failed North Korean missile launch.
"Only one B-1 bomber was able to take off. The other was scrubbed due to maintenance issues.
* This report focused on why there was one bomber, not two. It does not explain why China warns.
(d) Ryan Browne, Chinese Officials Warned US Bomber During 'routine' East China Sea Flyover. CNN, Mar 23, 2017 www.cnn.com/2017/03/22/politics/china-us-aircraft-warned
("The bombers had entered a controversial Chinese Air Defense Identification Zone (ADIZ) in the East China Sea, which covers a disputed" array of Senkaku islands)
(e) Despite sometimes called stealth, B1 bomber is not stealth, but "a low-level penetrator." Rockwell B-1 Lancer https://en.wikipedia.org/wiki/Rockwell_B-1_Lancer