Japanese authorities say they've discovered thousands of metal nameplates on bridges and tunnels have been stolen across the country.
The nameplates are inscribed with the dates of completion, and the names of the builders. Many of them are made of brass.
Cases of stolen nameplates came to light in Shimane Prefecture on April 1st.
That prompted state and local authorities to look into whether there are other cases.
Their investigation found that a total of 2,006 nameplates worth roughly 900,000 dollars have disappeared.
They say they've gone missing in 8 prefectures since April.
Fukui Prefecture topped the list with the number of nameplates stolen, at 762. Gifu Prefecture was second at 533, followed by Ishikawa at 328.
Officials in Ishikawa Prefecture say the stealing has continued even after they took preventive measures.
They welded bolts on the plates.
Police are investigating, but they've yet to find out who stole them or why.
The head of a nationwide non-ferrous metal recycling industry group, Hideyuki Kobayashi, says there may be a group targeting sparsely populated areas.
Jul. 5, 2014 - Updated 15:51 UTC