Japan and Australia urged calm on Sunday after Chinese military aircraft locked radar on Japanese fighter jets. Defence Minister Shinjiro Koizumi said Japan formally protested the incident.

He said China’s military aircraft J-15 took off from the Chinese carrier Liaoning near the southern island of Okinawa on Saturday and “intermittently” latched its radar on Japanese F-15 fighter jets on two occasions Saturday, for about three minutes in the late afternoon and for about 30 minutes in the evening.