Four Chinese patrol ships intruded into Japan's territorial waters off the Senkaku Islands in the East China Sea , Japan's NHK World reported.
The Japan Coast Guard said that the Chinese vessels entered waters off Uotsuri Island, one of the Senkakus.
The ships stayed in the waters for more than an hour and a half before moving to the contiguous zone just outside the territorial waters.
The four vessels first entered the zone on Thursday, shortly after four others left.
It's the 5th day this year that Chinese ships have entered Japanese waters off the Senkaku Islands. The last time was on February 6th.

Source: QNA