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 44-year-old man was in custody, the police said, after the child was attacked Wednesday. Other Japanese schools in China urged caution.

Some of Japan’s biggest companies urged the protection of employees in China, following the fatal stabbing in the mainland of a young Japanese boy.