A child enrolled in a Japanese school in Shenzhen, China, has died after being stabbed by an assailant on Wednesday, the Japanese government said.
Chinese authorities had said the victim was 10 years old and had been stabbed on the way to school on Wednesday. The suspected 44-year-old assailant was arrested on the spot.
The child died in the early hours of Thursday, Japanese foreign minister Yoko Kamikawa told reporters.
"I take the incident extremely seriously," she said.
"This should never happen in any country. Particularly, I sincerely regret that this despicable act was committed against a child on their way to school."
Japan has asked China to provide a detailed explanation of the facts and to take strong safety measures, she added.
Authorities in both Japan and China have not disclosed the nationality or gender of the victim. The website of the Shenzhen Japanese School says it is for children of Japanese nationality, and Japanese media said the victim was a boy.
The local Japanese chamber of commerce has asked the Japanese government to ensure the safety of its nationals in the area, the organisation said in a statement.
The attack took place near the school on the anniversary of an incident in 1931 that triggered war between China and Japan, a sensitive date at a time when diplomatic relations are in danger of deteriorating.
It was the second such attack near a Japanese educational facility in China in recent months.
Japanese Chief Cabinet Secretary Yoshimasa Hayashi declined to comment on any potential impact of the latest incident on bilateral ties.
In June, a man attacked a bus used by a Japanese school in the eastern city of Suzhou, resulting in the death of a Chinese national who tried to shield a Japanese mother and her child from the assailant.
Also on Wednesday, a Chinese aircraft carrier entered Japan's contiguous waters for the first time, the latest in a string of military manoeuvres that prompted a protest from Tokyo to Beijing.
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