A Chinese man has been indicted by the country's authorities over the fatal stabbing of a 10-year-old boy in September in the southern city of Shenzhen, Japanese Foreign Minister Takeshi Iwaya said Friday.

Iwaya said at a press conference in Tokyo that another Chinese man has also been indicted over a knife attack in June in Suzhou, near Shanghai, in which a Japanese family was injured and a Chinese bus attendant died.

"We will maintain close communication with China" regarding developments in the two incidents, Iwaya said. The cases have heightened safety concerns among Japanese citizens living in China.

In Shenzhen, the boy whose father is Japanese and mother Chinese died a day after being stabbed on Sept. 18 while on his way to school. The alleged attacker was detained by police at the scene.

While the suspect's motive has not been disclosed, the stabbing occurred on the 93rd anniversary of the Japanese bombing of a railroad track near Shenyang, which marked the start of the Manchurian Incident that led to Japan's invasion of northeastern China.

In Suzhou, the alleged attacker -- a man in his 50s, who was unemployed and moved to the city in the Jiangsu Province sometime before the stabbing -- was subdued after assaulting a mother and her child at a Japanese school bus stop on June 24.

The attendant, Hu Youping, 54, died from stab wounds days after attempting to stop him. Chinese authorities have yet to release information about the man's background and his motives.

Following the incidents, Japan has repeatedly asked China to take measures to prevent similar cases in the future.