Fire broke out around 9:50 p.m. Wednesday on a main wooden gate of Beomeo Temple and was contained about three hours later, they said.

The destroyed gate Cheonwangmun (The Gate for the Heavenly King) is one of the temple's major architectural structures that honors four mythical kings who each govern one of the directions of north, south, east and west of heaven.

Police said footage from a surveillance camera showed a man throwing an unidentified object at the gate and fire breaking out afterward. They were investigating several suspects who have records of arson.

About 30 fire trucks and 70 firefighters were dispatched to the scene. To prevent the spread of fire to other adjacent wooden treasures, the firefighters had to first dismantle Cheonwangmun with the consent of the temple authorities, the police said.

The four heavenly king statues set up at the destroyed gate were fortunately copies, with the originals preserved in the temple's small museum, they said.

Beomeo Temple was built in 678 during the Silla Kingdom and is one of the three major temples in Korea's southeastern region along with Haein Temple and Tongdo Temple.

Several major historic pieces of architecture have been destroyed by arson or natural fire in recent years, including the iconic gate of Sungnyemun, also called Namdaemun, at the center of Seoul and Naksan Temple in Yangyang County, Gangwon Province, on the east coast. (Yonhap News)