From The Japan Times (link):
China and South Korea have canceled participation in a multinational naval security exercise, the Japan Coast Guard said Sunday.
The drills began Saturday with Japan and three other participants — the U.S., Canada and Russia — a coast guard official said.
Although Japanese officials refused to give a specific reason for the cancellation, South Korea said it was because of concerns that part of the exercises may upset North Korea, whose nuclear ambitions are a major regional concern.
