China Coast Guard vessels began last month to issue warnings for Japanese Self-Defense Forces planes to leave airspace over and around the Japan-controlled, China-claimed Senkaku Islands in the East China Sea, sources familiar with the matter said.
The warnings via radio communications are based on Beijing's claim that SDF aircraft could violate Chinese territorial airspace around the islands, called Diaoyu in China, and have been made several times since January, the sources said Saturday.
They said Tokyo has refuted the claim and told Beijing through diplomatic channels that such warnings are "totally unacceptable," without publicly announcing the move in an apparent effort not to damage bilateral relations further.