Some Japanese companies in China have offered to send their staff and their families back home after a 10-year-old Japanese boy was fatally stabbed in the Chinese city of Shenzhen, a Japanese executive and employees of Japanese firms in Beijing said on Friday.

Japan's ambassador to Beijing has asked for more security for Japanese nationals in China after a 10-year-old Japanese boy was killed this week in a knife attack that was the second to target school students.

A 10-year-old Japanese student was stabbed near his school in Shenzhen, China, and has died, officials said, despite Tokyo's requests for enhanced safety.