Eight Japanese children have been killed and more than 20 others injured, several critically, by a man who burst into their elementary school classroom and began stabbing at random.
The attack, unprecedented in traditionally safe Japan, took place in the middle of morning classes at the elementary school in Ikeda, a suburb of the western city of Osaka.
While school shootings are becoming a grim part of life in the United States, no such random tragedy has ever struck a Japanese school.
Police were holding a 37-year-old man in custody.The man reportedly walked into a classroom and began stabbing schoolgirls with a 15-centimetre (6 inch) knife.
While the motive remained unclear, NHK national television reported the suspect had told police that he had taken ten times the usual amount of tranquillisers and that he was babbling garbled words.
"We were listening to an announcement over the loudspeaker, and then it was broken into by a scream and a noise like a desk falling down," a sixth-grade girl told Reuters. "Then I heard someone scream from below, 'Run!'"
A schoolboy said: "I saw a person who had fallen down. I also saw blood."
Witnesses reported that a woman with bloodstains on her blouse ran into a nearby supermarket calling for help.
The only previous school crime in recent years took place in 1998, when a 13-year-old Japanese boy stabbed a teacher to death after she asked why he was late for her English class.
Although Japan has traditionally been known for its safety, this has been changing in recent years, with the number of senseless crimes - often committed by teenagers -rising rapidly.
Last year, one 17-year-old boy bludgeoned passengers at a Tokyo subway station with a baseball bat after a fight with his father, another beat his mother to death with a metal bat, while a third stabbed an elderly neighbour to death because he wanted to experience killing someone.
The crimes are not limited to 17-year-olds, however. One of the grisliest incidents of recent years, the 1997 murder and beheading of an 11-year-old boy, was carried out by his 14-year-old playmate.
More recently, there has been a wave of incidents on Tokyo's crowded subways, including one in which a man was killed after by a fellow passenger enraged at his request for people to step back so he could board.