Neither side confirmed the nationality of the victims, but the school’s website describes it as a school for “Japanese children of Japanese nationality.”
The motive for the attack was not immediately known.
The incident occurred on the anniversary of the infamous Manchurian Incident, when Japan faked an explosion to justify its invasion of Manchuria in 1931, sparking a 14-year war with China.
“This is something that should never happen in any country,” Kimikawa said.
The stabbing incident in Shenzhen follows a similar one in June, when a man targeted a Japanese mother and her child in the eastern city of Suzhou.
The Japanese embassy in Beijing issued a statement on Thursday urging the Chinese government to “ensure that such incidents do not occur again.”
Chinese Foreign Ministry spokeswoman Lin Jian told a news conference Wednesday that an investigation into the incident was ongoing.
“China will continue to take effective measures to protect the safety of all foreigners in China,” he added.
Relations between Japan and China have long been rocky. For decades, the two sides have clashed over issues ranging from historical grievances to territorial disputes.
Some experts have expressed concern that nationalist sentiment within China could lead to increased violence against foreigners.
A knife attack in Suzhou in June also occurred near a Japanese school, with a Chinese man killed while trying to protect a Japanese mother and her child. Earlier that month, four American teachers were stabbed in the northern city of Jilin.
China has described both incidents as “isolated incidents.”
A former Japanese diplomat said Wednesday that the Shenzhen attack was “the result of many years of anti-Japanese education” in Chinese schools.
“This cost the precious lives of Japanese children,” Shingo Yamagami, the former Japanese ambassador to Australia, wrote on X.
After the stabbing incident in Shenzhen, some Japanese schools in China have contacted parents and put them on high alert.
The Guangzhou Japanese School has canceled some activities and banned speaking Japanese loudly in public places.
Earlier this year, the Japanese government requested about $2.5m (£1.9m) to hire school bus guards in China.
There were some comments on Chinese social media condemning the incident, with one user commenting: “Violence is not patriotism.”
