Prior to his entry into the school, the man, who works at a facility for disabled people, dropped by his house around 10:30 a.m. to take medication for his mental disease treatment and received a notice from the Patriots and Veterans Affairs Ministry that informed him that his application for appointment as a national meritorious person had been rejected, police said.

After hearing, "Arm yourself and fight against the world," in hallucination and being dissatisfied with the ministry's notice, the man took a knife from his house and entered the school. He was apparently allowed into the school office when he posed as a former student who had come to ask for a graduation certificate.

A team of special forces from the Bangbae Police Station was dispatched to the scene and overpowered the attacker after he fell to the ground showing symptoms of epilepsy, police have said. The team rescued the girl, ending the hostage situation after about an hour.

The victim is said to be unharmed and was sent to a nearby hospital for a further checkup. She left the hospital later after a doctor confirmed that she was showing no signs of post-traumatic stress disorder.

Police have confirmed the man, who has a history of schizophrenia, has been treated for his mental illness since July 2013.

Yang has been investigated three to four times on charges of assault. Each time he was arrested on suspicion of an assault, he showed symptoms of mental illness.

He, who graduated from the elementary school, has been working at the ward office-operated facility for disabled people since January this year.

Police said they will seek a warrant to arrest Yang later in the day on charges of taking a hostage and illegal entry into a special building. (Yonhap)