At least eight students were injured in a hammer attack at a university in Japan's Tokyo city on Friday, media reports said.

An emergency call was made around 3:45 p.m., reporting an attack by a student at Hosei University's Tama Campus in Machida, reported Japan's Kyodo news agency.

According to reports, the attacker was identified as a 22-year-old South Korean woman.

She was subdued and arrested.

Investigative sources quoted the suspect as saying she was "frustrated" after being ignored by a group of students and used a hammer she found on campus, Kyodo news agency reported.

All eight people sustained minor injuries.

This was a rare incident of violent crime in the country.