Three Chinese patrol ships have entered Japanese territorial waters off the Senkaku Islands in the East China Sea, Japan's NHK World reported. 
The vessels were spotted off Uotsuri Island, and navigated in Japanese waters for about 90 minutes before leaving by around noon. 
The three ships were later observed navigating in the contiguous zone just outside the territorial waters, about 26 kilometers southwest of Uotsuri Island.
The Coast Guard repeatedly warned the vessels not to enter Japanese waters. 
This is the 35th day this year that Chinese patrol ships have entered Japanese waters. Their last incursion was on December 5th. 
Japan's government said the Senkaku Islands are the nation's inherent territory. 
Japan controls the islands, which are claimed by China and Taiwan.

Source: QNA