But its current mayor annoyed Nanjing by telling a visiting official delegation that he doubted the Nanjing Massacre in 1937 ever happened.

The foreign affairs office of Nanjing municipal government said it was "shocked" by his remarks.

"Some Japanese politicians' recurring attempts to deny history have deeply hurt Chinese people's feelings, and influenced healthy and stable Sino-Japanese cooperation."

According to Japan's Kyodo News, the Nagoya government said it felt "terrible regret" about Nanjing's announcement.

According to Asahi News, China's consulate-general in Nagoya called the city's international exchange department to protest, saying that the mayor was "thoughtless" to cast doubts on history based on his individual presumptions over why his father Kaneo Kawamura, a Japanese soldier, was "welcomed" by local residents in Nanjing in 1945.

"We forgive that period of history, but it doesn't mean it can be forgotten, or be denied," said Xia Shuqin, a survivor of the Nanjing Massacre.

Xia was stabbed three times in the massacre, and seven members of her family were killed. Her experience was recorded in the diary of John Rabe, a German businessman well known in China for his great efforts to save Chinese civilians from Japanese troops.

"I hope those Japanese politicians will no longer hurt our feelings," said the 84-year-old.

"I'd like to confront those Japanese people who deny the Nanjing Massacre."