A Chinese man who claimed his grandmother was forced into sexual slavery for the Japanese military during World War II was arrested on Sunday for hurling four Molotov cocktails at the Japanese Embassy building in Seoul.

The 36-year-old, identified by his surname Lui, was caught for throwing four Molotovs at the wall of the Japanese Embassy in downtown Seoul at around 8:18 a.m., officials at Jongno Police Station said.

No injury or property damage was reported in the incident, they said.

The man from Guangzhou, who came to South Korea with a tourist visa on Dec. 26 via Japan, also claimed he set fire to Tokyo’s Yasukuni Shrine before leaving the country, officials said.

“We discovered Lui is the one who claimed to have set fire to the door of Japan’s Yasukuni Shrine last month,” a police official said.

The controversial shrine, often seen as a symbol of Japan’s wartime aggression, is regularly a source of friction with Japan’s neighbors, who say it honors those responsible for terrible crimes.

Police said they are questioning Lui to figure out the motivation behind his attack. Lui said he attacked the embassy in protest of Japan’s refusal to apologize for its war crimes.

Historians say tens of thousands, perhaps hundreds of thousands, of women from Korea and other Asian countries were forced to serve as sexual slaves for front-line Japanese soldiers during the war.

The subject of sex slaves, euphemistically called “comfort women,” is one of the most emotional unresolved issues between South Korea and Japan. (Yonhap News)