The incident on Monday during after-school care has shocked the nation and prompted the country’s acting president to instruct reviews of school safety standards.

The female suspect is receiving hospital treatment for self-inflicted wounds following the death of the young girl in an audio-visual room on the second floor of the school, said Yuk Jong-myeong, chief of Daejeon’s western district police station.

The suspect, reported to be in her 40s, told police that she had recently returned to work after a period of leave for health reasons, Yuk said.

She told police she has received treatment for depression since 2018.

After the girl, a first-grade student, was reported missing at 5.15pm local time Monday (7.15pm AEST), police and family members searched throughout the school and surrounding areas.

Her grandmother found her in the audio-visual room around 5.50pm (7.50pm AEST). The girl was rushed to the hospital, where she was pronounced dead.

Choi Sang-mok, who is serving as the country’s acting leader due to President Yoon Suk Yeol’s impeachment over a martial law imposition in December, called for a thorough investigation into the incident and instructed education authorities to “implement necessary measures to ensure such incidents never happen again.”

Visitors laid flowers and condolence letters at the gate of the school, which was closed on Tuesday.