Tsutomu Miyazaki, the death row inmate convicted of murdering four young girls in 1988 and 1989 in Tokyo and Saitama Prefecture, was executed Tuesday, the Justice Ministry said.

Miyazaki, 45, was among the three death row inmates hanged the same day. With their execution, the number of inmates executed under the orders of Justice Minister Kunio Hatoyama, who has been in the post since last August, came to 13.

''After careful deliberation, we executed three inmates today,'' Hatoyama said at a news conference.

Miyazaki, detained at the Tokyo Detention House, was executed two years and four months after the Supreme Court finalized his death sentence in February 2006, which ended trials of him that had lasted 16 years.

On Jan 17, 2006, the top court ruled that an extreme character disorder could be found in Miyazaki, but that he was completely mentally competent at the time of the crime, denying he had any mental disorder that would make him unable to bear criminal responsibility.

The top court said Miyazaki abducted and killed the four girls in Tokyo and neighboring Saitama Prefecture ''to satisfy his own sexual desire and appetite to own videotapes with footage of corpses.''

He confessed to having killed four girls, aged between four and seven, in Tokyo and its suburbs and eating some of the remains of two of them.

Miyazaki mutilated the bodies of the victims, slept next to the corpses and drank their blood.

He sent letters to the media under a woman's name claiming responsibility for the crimes and sent a box containing the remains of a slaughtered girl to her family.

In a letter to Kyodo News just before the Supreme Court ruling, Miyazaki maintained his innocence and said he thought he ''did a good thing.''

During the nearly two-decade judicial process, Miyazaki never uttered a word of remorse to the victims and their families. He cryptically said that a "rat man" -- a cartoonish image of which he drew -- committed the crimes.

He also distanced himself from his family. When his father, unable to come to terms with what his son did, jumped into a river to his death in 1994, Miyazaki wrote to a publisher: "I feel refreshed."

But court-appointed psychiatrists agreed with defense lawyers that Miyazaki was mentally ill. One finding was that Miyazaki suffered from a multiple personality disorder, while a second said he was schizophrenic.

Hirokazu Hasegawa, a clinical psychologist who saw Miyazaki in 2006, said the killer believed his crimes would resurrect his grandfather, who died three months before the grandson committed his first crime in 1988.

"What he told me lastly was 'Please tell the world that I'm a gentle man,' " Hasegawa said at the time.

The two other executed inmates are Shinji Mutsuda, 37, and Yoshio Yamasaki, 73.

Mutsuda was convicted of killing the 32-year-old operator and the 33-year-old manager of a sex service business at a Tokyo apartment in 1995, stealing some 200,000 yen and drawing 40 million yen from the bank account of the operator in conspiracy with his twin brother.

Yamasaki was convicted of killing a 49-year-old woman in Miyagi Prefecture in 1985 and a 48-year-old man in Kagawa Prefecture in 1990 in conspiracy with acquaintances of his.

Amnesty International Japan criticized the fast pace of executions under Hatoyama, saying in a statement, ''The latest executions were carried out only two months after the previous ones. That indicates Japan is following a path of mass executions.''

With 137 countries having legally or effectively terminated capital punishment, Japan is going against the international trend of abolishing the death penalty, the human rights group said. Following Tuesday's executions, the number of inmates on death row now stands at 102.

Chief Cabinet Secretary Nobutaka Machimura suggested at a separate news conference that the acceleration of executions reflects the recent increase in death sentences and the number of death row inmates.

© Wire reports