Chinese coast guard ships remained in Japanese territorial waters near the Senkaku Islands in the East China Sea for a record 80 hours and 36 minutes before the three vessels left the area, the Japan Coast Guard said.
It is the longest period Chinese ships have invaded the waters since the Japanese government placed the islets under state control in 2012.
The group of uninhabited islets, which China claims and calls Diaoyu, has long been a source of friction between the two Asian neighbors.
At first, a total of four Chinese vessels successively entered Japanese waters near the Senkakus from around 11:10 a.m. Thursday, according to the coast guard.
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One of them moved to the contiguous area, outside territorial waters, on Saturday night, but the remaining three continued to navigate Japanese waters, he said. When they appeared to be following a pair of Japanese fishing boats, the coast guard patrol boat warned them to leave Japan waters.
The three boats left the adjoining area around 7:45 p.m. Sunday, according to the coast guard.
Of the four that entered Japanese waters, one was equipped with what appeared to be an automatic cannon, Kyodo News noted.
It was the 67th consecutive day that a Chinese ship was sighted near the Senkakus, including in the contiguous zone, the coast guard said.
