Serious sex offenders are required to register their address and personal profile with the police, but 64 of them have disappeared and 339 registered false information or failed to update their addresses.

The National Police Agency on Tuesday said it reviewed its database of 4,509 offenders with a history of serious sex crimes from Aug. 27 to last Friday. The 64 whose whereabouts are unknown were put on the wanted list, and those who submitted false information have been charged.

Of the 4,509, 3,487 committed sex crimes against children and adolescents. Of those registered on the police database, over 75 percent or 3,487 committed sex crimes against children or adolescents.