Photo/Illutration First responders gather at a building on the Tama Campus of Hosei University on Jan. 10 after the attack in a lecture hall. (Ikuro Aiba)

Students at Hosei University in Tokyo recounted how screams suddenly punctuated the quiet of a lecture hall after a classmate went on a rampage by swinging a hammer at those seated close by.

The incident on Jan. 10 at the Tama Campus in western Tokyo left eight students injured, but none was in a critical condition.

A 22-year-old student from South Korea was arrested on the campus in Machida city.

“I got frustrated,” she reportedly told investigators.

The incident occurred in a large lecture hall capable of holding about 100 students on the second floor of a Faculty of Social Sciences building.

A 20-year-old student of the faculty recalled she was in the lecture hall shortly before 4 p.m. when she heard a scream from the back of the room.

Turning around, she saw students scrambling to flee. One had blood pouring down her face.

Not understanding what had transpired, the 20-year-old also ran toward the front of the classroom. When she turned around again, she saw a classmate holding a hammer measuring about 30 centimeters in length.

“I was so shocked that such a thing could happen during a university lecture,” the student said. “I was so scared my hands were shaking for quite some time.”

A 20-year-old student in the Faculty of Social Policy and Administration was sitting in the fifth row from the back of the lecture hall.

He heard a dull sound and thought that perhaps  someone had been punched and a fight was about to start. When he turned around, he saw the attacker swinging a hammer and hitting students on their heads.

“I always thought that scary incidents shown on TV news would never occur near me, but I now know it can happen to anyone,” he said.

A third-year student in his 20s said the perpetrator showed no expression during the attacks. When the hammer slipped from her hand, she started slapping others with her bare hand and hurled her mobile phone to the floor.

“Scary is the only way to describe what happened in the classroom,” the student said. “I thought there was no way to prevent it.”

A fourth-year student in the Faculty of Social Sciences was in a nearby building when the incident occurred.

“I learned about the incident when a friend sent me a Line message asking if I was OK,” the student said. “I never though such an incident would occur on campus.”

He saw an ambulance park outside another building used to treat the injured students.