Tokyo’s embassy in Beijing has separately urged its nationals there to refrain from speaking loudly in Japanese.
A Fukushima businessperson told the Kyodo news agency that his four restaurants and pastry shops received a total of about 1,000 calls on Friday, mostly from China.
His businesses had to unplug their phones, Kyodo said.
Fukushima city mayor Hiroshi Kohata said in a Facebook post Saturday that the city hall had received around 200 similar calls in two days, while local schools, restaurants and hotels also became targets.
“I will report this to the Japanese government and demand action,” he wrote in his post.
Chinese social media users shared videos of themselves making calls to Japanese numbers, including restaurants in Fukushima.
TEPCO is releasing more than 500 Olympic swimming pools’ worth of wastewater used to cool Fukushima’s damaged reactors, three of which went into meltdown in March 2011 when they were hit by a massive earthquake and tsunami that killed about 18,000 people.
The water has been filtered of all radioactive elements except for tritium.
The Japanese environment ministry said Sunday that a fresh test of Fukushima coastal water showed no elevated levels of tritium.
The ministry added that the water samples did not show signs of gamma radiation that can come from other radioactive materials such as caesium.