A teenage boy has been charged with slashing a schoolgirl’s face 20 times in a horrific, random attack at Logan, south of Brisbane.

The girl underwent surgery after she was repeatedly slashed in the face as she walked to school through a pedestrian tunnel under the Logan Motorway at Kingston on Thursday.

She managed to get away, running towards Kingston State College to get help.

A 17-year-old boy has been charged with acts intended to cause grievous bodily harm following a manhunt that involved about 30 police officers.

He is expected to face the Children’s Court on Friday but due to his age, those proceedings cannot be reported.

Detective Acting Inspector Grant Ralston said the girl was walking alone to school when she was targeted “for no reason”.

“The male is believed to have had possession of some sort of cutting instrument, like a box cutter, and continually struck the young girl on the right side of the face causing extensive injuries,” he said.

“She fought as best she could and eventually after being struck approximately 20 times to the face, incredibly, she managed to pick herself up and run towards her school at Kingston.”

The girl was bleeding profusely when she reached help. She was rushed to the Queensland Children’s Hospital where she remains in a stable condition after undergoing surgery.

“The young girl was minding her own business on her own, walking to school with her school bag, and this male offender had struck the victim for no reason,” Inspector Ralston said.

“The young girl is very brave,” he added.

The girl told police the attack lasted just 10 to 15 seconds.