Two Chinese citizens protested in front of Japan’s Yasukuni Shrine Wednesday, one of whom was arrested.

One protester held a banner that read "protest the Nanjing massacre” (毋忘南京大屠杀), and burned a replica of the headstone of notorious Japanese general Hideki Tojo.

The man was arrested on suspicion of criminal trespassing, and his companion is being investigated, according to the Tokyo police, China’s state-run Huanqiu.com reported, citing Kyodo News and NHK.

The Yasukuni Shrine is a monument in Tokyo that commemorates Japanese war deaths, including more than 1,000 convicted war criminals. It has long angered China, where millions of citizens were killed by the Japanese during World War II.

The Nanjing Massacre was a particularly brutal chapter in the war. Hundreds of thousand of Chinese were raped and murdered over a six-week period in December 1937-January 1938.