Two China Coast Guard ships left Japanese territorial waters near the disputed Senkaku Islands in the East China Sea over the weekend after staying there for a record length of time, according to the Japan Coast Guard.
The two vessels stayed in the waters around the Senkakus, which are also claimed by China, where they are known as the Diaoyu, for 39 hours and 23 minutes after crossing into Japan's territory at around 2:25 a.m. Saturday.
This was longer than the 30 hours and 17 minutes Chinese government ships recorded Friday, the previous longest stay since Japan brought the islands under state control in September 2012.
The Japan Coast Guard had urged the Chinese ships not to approach a Japanese fishing boat and to leave the waters immediately.
Late last month, China criticized a Japanese island municipality that has administrative authority over the disputed islands for its attempt to rename an area covering the Senkakus.
The city assembly in Ishigaki, Okinawa Prefecture, passed a resolution on June 22 to change the name of the area to "Tonoshiro Senkaku" from "Tonoshiro."
Japan, meanwhile, lodged a protest with China on Friday over the Chinese vessels entering Japanese territorial waters around the islets, the first intrusion since the municipality passed the resolution.
Chinese ships have been spotted around waters near the islets for 84 days in a row as of Monday, the longest streak since the islands came under state control despite some recent thawing in bilateral relations. The two countries' ties have been frayed over the Senkakus issue and conflicting views over history related to World War II.