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.

In a call with China’s vice-foreign minister Sun Weidong on Thursday, Japan’s ambassador Kenji Kanasugi “strongly urged” Beijing to share detailed information about the incident, which was the second targeted attack on Japanese schoolchildren in China in recent months.