Tokyo, May 8 : Four Chinese patrol ships temporarily entered Japanese territorial waters near the Senkaku Islands in the East China Sea on Monday, coast guard officials said.
According to the officials, the incursion occurred in the waters off Uotsuri Island, public broadcaster NHK reported.
The ships stayed in the waters for over an hour before leaving.
The ships had been navigating in the contiguous zone just outside the territorial waters since April 30.
The officials have warned the ships to stay away from Japanese waters.
This is the 12th incursion by Chinese patrol ships this year.
The previous one was on April 24.
Japan's Foreign Ministry lodged a protest with the Chinese Embassy in Tokyo over the latest incursion.
The ministry made a similar protest to the Chinese government through the Japanese Embassy in Beijing.
