A Nagasaki prefectural government official was arrested Tuesday after paper cranes symbolizing peace were found burned at a Nagasaki park commemorating the victims of the atomic bombing of the southwestern Japan city in 1945.

A man passing by the Nagasaki Peace Park reported to firefighters around 6:20 a.m. that a large number of origami cranes were on fire. The 23-year-old man, arrested on the spot on suspicion of property damage, has admitted to using a lighter to set fire to the paper cranes, police said.

Photo shows the scene where paper cranes were found burned in Nagasaki Peace Park in Nagasaki on June 13, 2023. (Photo courtesy of Nagasaki prefectural police)(Kyodo)

The prefectural official has been undergoing treatment for illness, and the police are investigating his motive and other details.

Visitors to the site sometimes donate paper cranes in groups of a thousand to pray for peace, following a tradition in Japan that making a thousand folded paper cranes makes wishes come true such as recovery from illness or success in school sporting events.

No one was injured in the incident near a memorial made from a wall of the former Urakami Cathedral destroyed in the bombing, but a stand for offering flowers and other items was left damaged, according to the police and the firefighters.

The story of Sadako Sasaki, a Hiroshima atomic bombing survivor who died aged 12 of leukemia after folding the paper cranes in a bid to wish for recovery, has since made them an anti-nuclear symbol.