Japan on Tuesday executed three people including notorious serial killer Tsutomu Miyazaki, a fetishist convicted of murdering four little girls and eating some of their bodies, officials said. Miyazaki, 45, was nicknamed the "killer nerd" for his obsession with sexual cartoons and pornography. But defence lawyers contended he was mentally ill and could not be held fully responsible for his actions. Japan is the only major industrialised nation other than the United States to apply the death penalty and has been stepping up the pace of executions, which enjoy wide public support. "We are carrying out executions by selecting the people whom we can execute with a feeling of confidence and responsibility," Justice Minister Kunio Hatoyama told a news conference. The executions come one week after Japan saw a deadly stabbing spree in a Tokyo neighbourhood known for nerd culture, carried out by a troubled young auto worker who sent messages of despair over the Internet.