A record number of minors were victims of crimes such as child pornography and prostitution through social media in the first half of 2017, police data showed Thursday.

A total of 919 people under 18 fell victim in the January to June period, up 30 from a year earlier and the highest number since comparable data became available in 2008. Female high school and junior high school students accounted for nearly 80 percent of all victims, according to the National Police Agency.

More than 30 percent of the total, or 327 victims, used Twitter, while users of online services that enable them to communicate with multiple persons simultaneously increased.