Photo/Illutration A stone pillar at Yasukuni Shrine in Tokyo’s Chiyoda Ward was partially covered after it was vandalized on Aug. 19. (Hiromichi Fujita)

Graffiti was discovered on a stone pillar at Tokyo's Yasukuni Shrine on Aug. 19, marking the second such act of vandalism at the controversial war memorial this year.

Shrine staff called police in the early morning after discovering two Chinese characters meaning "Toilet" written on the lower part of a pillar at the shrine entrance. The graffiti was apparently written in black marker.

Several other words were also found on the pillar, which bears the shrine's name, according to police.

Additionally, the letters "SB" were written on the pillar's foundation.

In May, the same pillar was graffitied with the word "Toilet" in English in red spray paint.

The Metropolitan Police Department obtained arrest warrants for three Chinese men on suspicion of destruction of property.

One of the men, who resides in Saitama Prefecture, was arrested and prosecuted in July. The other two have already returned to China, according to police.

The Shinto shrine is a frequent source of historical disputes and international tensions because of the 14 Class-A war criminals from World War II enshrined there along with the nation’s war dead.