Japan's vice foreign minister Masataka Okano on Monday summoned the Chinese ambassador over the numerous instances of harassment phone calls from China regarding the release of Fukushima's treated radioactive water, Japan's foreign ministry said.

In a statement, the ministry said the calls were also occurring at Japanese facilities in China, and urged the government to take appropriate action promptly and ensure the safety of Japanese citizens. (Reporting by Kiyoshi Takenaka Editing by Chang-Ran Kim)