A man arrested over a recent knife attack on passengers on a commuter train in Tokyo also considered bombing the city's famous Shibuya intersection, investigative sources said Tuesday.
Yusuke Tsushima, 36, was quoted by the sources as saying he wanted to target "happy-looking couples" there.
Tsushima went on a stabbing rampage Friday on an Odakyu Electric Railway train. A total of 10 passengers were injured, including a 20-year-old female university student who was seriously injured with multiple stab wounds.
After fleeing the scene, Tsushima was detained later Friday and then arrested on Saturday on suspicion of the attempted murder of the female student.
Tsushima told investigators that he wanted to kill her because she looked like "a winner" in life, according to the sources.
"I developed a desire to kill women who appear to be successful and couples who looked happy after a woman made a fool of me at a university club," he was quoted as telling investigators.
Earlier on the day that he attacked the train passengers, a female store clerk at a grocery store in Tokyo had called the police after accusing him of shoplifting, the police said.
Tsushima, who was released after officers questioned him about the shoplifting incident, told investigators that he had wanted to kill the clerk but shifted his target to the train passengers because he noticed the store was about to close.
Train security cameras captured footage of a man likely to be Tsushima stabbing the female student in her chest and slashing her back several times on the train at around 8:30 p.m. Friday.
The other nine victims, comprising both women and men, were stabbed by Tsushima or sustained injuries while trying to escape the rampage, according to the investigation.