Japanese and South Korean military aircraft flew through this disputed airspace over the east China sea, directly challenging China and its new air defence zone.
(SOUNDBITE) (Japanese) JAPANESE CHIEF CABINET SECRETARY, YOSHIHIDE SUGA, SAYING:
"Even since China has created this airspace defence zone, we have continued our surveillance activities as before in the East China Sea including in the zone."
Tensions have ratcheted up since China's announcement of the zone.
But on Thursday Beijing seemed to soften its demand on commercial airlines.
(SOUNDBITE) (Mandarin) CHINESE FOREIGN MINISTRY SPOKESMAN QIN GANG SAYING:
"The East China Sea Air Defence Identification zone is not aimed at normal international flights. We hope that relevant countries airlines can proactively cooperate, so there is more order and safety for flights."
It is a group of islands here in the East China sea that lies at the heart of a feud between Japan and China.
Both co