Overall school violence has been on a steady decline in recent years, but the number of juvenile sex offenders has spiked significantly, police data showed on Sunday.

The number of teenagers arrested for acts of school violence totaled 13,584 last year, marking a decrease of 3 percent from 14,000 in 2017, according to the data from the National Police Agency (NPA).

School violence is classified into four types -- sexual violence, assaults, extortion and others -- and offenders include elementary, middle and high school students and out-of-school youths.

Contrary to the downward trend in overall school violence, the number of teenagers arrested for sexual offenses, including rape, forced harassment and illegal shooting, surged 80.5 percent from 1,695 in 2017 to 3,060 last year, the data showed.

Among the 40,951 school violence offenders caught by police between 2017 and 2019, out-of-school youths accounted for the largest number at 15,196, followed by high school students (12,718), middle school students (11,231) and elementary school students (1,806).

"Increasing sexual offenses committed by teenagers are mostly digital sexual crimes," said Rep. Kim Young-bae of the ruling Democratic Party, who released the NPA data.

"The authorities should strengthen relevant education for students and adolescents and more aggressively crack down on harmful video content," he said. (Yonhap)