By Zhao Wei, Sina English
Japan's deputy foreign minister Kenichiro Sasae again summoned Chinese ambassador Cheng Yonghua late last night to lodged its second protest amid the Diaoyus row, calling it "extremely serious", after another Chinese patrol ship approached waters off the Diaoyu Islands in the East China Sea.
According to Japanese media, Japanese coastguard said the Chinese patrol ship, the Yuzheng 35001, was seen approaching waters off the the Diaoyu Islands again around 5 p.m. on Thursday and they were ordered to "remain on high alert".
Japan's Kyodo News reported that two other Chinese fishery patrol ships, Yuzheng-202 and Yuzheng-33001, were also patrolling in the adjacent waters of Diaoyu Islands Thursday night.
On July 11, three Chinese fishery patrol ships, Yuzheng-202, Yuzheng-204 and Yuzheng-35001, approached waters off the the Diaoyu Islands around 2 a.m. on a routine mission within China's exclusive economic zone in the East China Sea.
Immediately afterwards, Japan's Deputy Minister for Foreign Affairs Kenichiro Sasae summoned the Chinese ambassador Cheng Yonghua to lodge protests, claiming what happened is "intolerable".
Cheng immediately rebuffed Japan's protests and reiterated China's position on the issue, saying Diaoyu Islands and surrounding waters are an integral part of Chinese territory.