Over 400,000 nuisance calls have been made to the Japanese Embassy in Beijing since the release of treated radioactive water from the crippled Fukushima nuclear power plant into the sea began in late August, Japanese government sources said Tuesday.

On the back of growing anti-Japan sentiment in China, the daily number of harassing calls received by the embassy peaked at more than 40,000 on Aug. 25, a day after the ocean discharge started, and has stayed at around 10,000 recently, they said.

Tokyo has repeatedly asked the Chinese government to deal with the calls, saying they impede operations at the embassy, but the situation has yet to improve, according to the sources.