Photo/Illutration Graffiti was scratched on Chionin temple's Sanmon gate, a national treasure. (Yoshiaki Arai)

KYOTO--Police have opened an investigation into graffiti scratched into a pillar of the Sanmon gate, a centuries-old national treasure at Chionin temple, the main place of worship of the Jodo sect of Buddhism.

The scratches are about 18 centimeters long and 12 cm wide and appear on the pillar about 160 cm from the base, according to the Higashiyama Police Station.

The damage, apparently caused by a hard object, looks like the letters “S” and “D.”

Kyoto prefectural police are investigating the matter as a possible violation of the cultural properties protection law.

A temple employee found the scratches at around 2 p.m. on June 18 and inspected the damage with officials from the city’s cultural property protection section on June 19. The temple employee notified police at 1:45 p.m. that day.

The Sanmon gate was built in 1621 in the early Edo Period (1603-1867) on the orders of Hidetada, the second Tokugawa shogun.

The gate is 24 meters high and 50 meters wide, making it one of the largest wooden gates still standing in Japan. A Buddhist hall sits on the upper level.

The central government designated the gate a national treasure in 2002.