TOKYO — A man convicted of murder for killing and dismembering nine people in his apartment near Tokyo was executed Friday, Japan’s Justice Ministry said.

Takahiro Shiraishi, known as the “Twitter killer,” was sentenced to death in 2020 for the killings in 2017 of the nine victims, most of whom had posted suicidal thoughts on social media. He was also convicted of sexually abusing female victims.

The execution was carried out as calls grow to abolish capital punishment in Japan since the acquittal of the world’s longest-serving death-row inmate Iwao Hakamada last year.

Shiraishi was hanged at the Tokyo Detention House in high secrecy with nothing disclosed until the execution was done.

Police arrested him in 2017 after finding the bodies of eight females and one male in cold-storage cases in his apartment.

Investigators said Shiraishi approached the victims via Twitter, offering to assist them with their suicidal wishes. He killed the eight women, including teenagers, after raping them, and also killed a boyfriend of one of the women to silence him.

Japan’s suicide rate ranks among the world’s highest. Following a recent decline, the number has climbed back this year as people were hit by the effects of the COVID-19 pandemic.

Japan’s crime rate is relatively low, but it has seen some high-profile mass killings in recent years.