Six schoolchildren were injured after a depressed teenage dropout went on a violent rampage and attacked young students with a shovel at an elementary school in southern Seoul, police said Friday.

The 18-year-old boy surnamed Kim broke into the school's campus shortly before noon and wielded the entrenching shovel in a classroom, hurting three girls and three boys, the Bangbae Police Station said, adding the attacker was also carrying a toy gun.

Kim continued his rampage for five minutes before being subdued by a male teacher from the next classroom, according to the police.

Sustaining minor injuries, the injured students were sent to a nearby hospital for treatment, police said.

They said Kim had dropped out of a high school in Incheon, west of Seoul, and underwent two weeks of treatment in a mental clinic for depression last year. Police are interrogating Kim over the motive of the rampage. (Yonhap News)