Chinese coast guard ships lingered 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 Sunday evening, the Japan Coast Guard said.

It is the longest period Chinese ships have intruded into the waters since the Japanese government put 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.

Initially, a total of four Chinese vessels entered Japanese waters near the Senkakus in succession from around 11:10 a.m. on Thursday, according to the coast guard.

One of them moved to the contiguous zone outside territorial waters on Saturday night, but the remaining three continued to sail in Japanese waters, it said. As they appeared to follow a pair of Japanese fishing boats, the coast guard's patrol boat warned them to leave Japan's waters.

The three ships left the contiguous zone by around 7:45 p.m. Sunday, the coast guard said.

Of the four that entered Japanese waters, one was equipped with what appeared to be an autocannon, it said.

It was the 67th consecutive day that a Chinese vessel was spotted near the Senkakus, including in the contiguous zone, the coast guard said.

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