An elderly man has confessed to starting the fire that destroyed the historic Seoul landmark of Sungnyemun Sunday night.

The Seoul Namdaemun Police Station told reporters it arrested Monday a suspect identified only by his surname Chae.

According to police, the 69-year-old Chae climbed a ladder to enter the 600-year-old wall gate at 8:45 p.m. Sunday. He sprinkled thinner inside the two-story wooden structure and used a disposable lighter to start the fire, escaping by taxi immediately after.

The man said he had surveyed the monument twice last year in preparation for the crime. He told police he did it because he was unhappy with the compensation the government offered for land it had taken from him.

Chae had a previous conviction for setting fire to a building at Seoul's Changgyeong Palace in 2006. But that sentence had been suspended.

Investigators have asked the National Institute of Scientific Investigation to analyze evidence including Chae's clothes and a bottle of thinner. Police are looking into whether he had an accomplice.