Tokyo police said Thursday they will issue smartphones to some officers and use Internet message boards and other means of communications popular with minors to more effectively prevent juvenile delinquency.

The Metropolitan Police Department will introduce the measure in December as computers and conventional cellphones are not effective in dealing with Internet message boards accessed via smartphone apps, officials said.

About a dozen smartphones will be given sometime in December to officers in a division dealing with youth problems and to some police stations.

Tokyo police began a trial of the system in April in which officers monitored Internet message boards and contacted minors when they found questionable posts that could lead to juvenile delinquency. The officers initially disguised their identities, only revealing who they were when making contact with individuals and then issuing warnings.