The killing of a Japanese schoolboy in the Chinese city of Shenzhen has sparked worry among Japanese expats living in China, with top firms warning their workers to be vigilant. Toshiba and Toyota have told their staff to take precautions against any possible violence,

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 has formally requested that China provide a comprehensive explanation regarding the circumstances of the attack in which a 10-year-old boy enrolled at a Japanese school in the Chinese city of Shenzhen was stabbed to death by a 44-year-old assailant.