Four China Coast Guard vessels entered Japanese territorial waters around the disputed Senkaku Islands in the East China Sea on Sunday, prompting Japan to lodge a protest with China. 
The ships entered the waters near the Japanese-administered uninhabited islands, which China claims and calls Diaoyu, the first such move by Chinese government ships since Aug. 17, and sailed for about an hour before leaving the area, according to the Japan Coast Guard. 
A patrol boat of the 11th Regional Coast Guard Headquarters based in Naha, Okinawa Prefecture, warned the Chinese vessels, including one apparently equipped with guns, to leave the waters. 

Source: QNA