A man arrested for killing seven people in a knife rampage on a crowded Tokyo shopping street posted dozens of warning messages on the Internet in the hours leading up to the attack, Japanese media reported on Monday.
Japanese police arrested a 25-year-old blood-spattered man at the scene for driving a truck into a crowd of Sunday shoppers in Akihabara, Tokyo's biggest electronics shopping district, and then walking down the street stabbing people at random.
Passers by prayed and dropped flowers on Monday at the scene of the attack, as a bewildered Japan tried to make sense of the latest in a series of random acts of violence.
Before the rampage in Akihabara, the arrested man, Tomohiro Kato, had warned on an Internet site that "I will kill people in Akihabara", Japanese media reported.
"I will crash my car and when the car becomes unusable, I will use a knife. Good-bye, everyone!," the man wrote on his Internet site early Sunday morning, the Asahi newspaper said.
The Mainichi newspaper said Tokyo police had heard of similar posts on another Internet site, but could not stop the attacks.
"I'm used to acting like a good person. I can fool everyone easily," Kato wrote, adding he was struggling to make friends.
In the last of more than two dozen Internet postings, he wrote a few minutes before the truck was rammed into the crowd: "The time has come."
Sunday's attack followed the killing of one person in a random stabbing outside a train station north of Tokyo in March, while five were hurt in a similar attack in January.
Also in March, a teenager pushed a stranger under a train in western Japan, saying he wanted to kill someone.
The latest attack sparked talk among Tokyo residents of failing communities and declining morality in a country proud of its low crime rate.
"Recently, peoples' relationships have become strained," said 29-year-old Taishi Ikeda, who works in the publishing industry. "There's no-one to talk to when you're troubled."
