Three people are believed to be dead and 16 people, including eight schoolchildren, have been injured in a stabbing in Japan's Kawasaki city.
Two children and an adult were without vital signs after the stabbing, southwest of central Tokyo, national broadcaster NHK said, citing police.
Footage broadcast on local TV stations showed multiple police cars, ambulances and fire engines at the scene.
Emergency medical tents were put up to treat the wounded.
"A man stabbed them," a spokesman for the fire department, Dai Nagase, earlier told AFP.
"We received an emergency call at 7.44am which said four elementary schoolchildren were stabbed."
The suspect was detained on the spot and was badly hurt after stabbing himself in the shoulder.
NHK said the man, likely in his 40s to 50s, reportedly began slashing at people waiting at a bus stop.
Two knives were found in a nearby park, it said.
The attack took place at the time of the morning commute and school run.
"I heard the sound of lots of ambulances and I saw a man lying near a bus stop bleeding," a man, who was not identified, told NHK.
"There is another bus stop near the elementary school and I also saw elementary schoolchildren lying on the ground ... It's a quiet neighbourhood, it's scary to see this kind of thing happen," he said.
Rescuers work at the scene of an attack in Kawasaki. Source: AAP
Japan has one of the lowest rates of violent crime in the developed world and mass attacks are extremely rare.
