Tokyo  - Ten Taiwanese ships entered Japanese territorial waters in the East China Sea Monday near Diaoyu Islands to protest against Japan's handling of a ship collision last week.

The Japanese coast guard warned the Taiwanese vessels with 12 activists and 30 journalists onboard to leave the area, while patrol boats were sent to monitor the ships.

A few hours after the warning, the ships left the waters, according to media reports.

The sea protest came after a Japanese coast guard vessel sank a Taiwanese boat near the Diaoyus on Tuesday.

Thirteen Taiwan fishermen and three crew were rescued from the sea by the Japanese crew.

The Japanese side claimed the boat intruded into its territorial waters, but the boat captain stressed the boat was on innocent passage.

The Japan Coast Guard filed papers on the captain of the sunken Taiwanese ship and the Japanese captain of the patrol vessel Saturday to Japanese public prosecutors on suspicion of professional negligence.

Taiwan Friday recalled its de facto ambassador to Tokyo to protest against Japan's handling of incident after Tokyo refused to apologize and compensate for the captain's loss. Taiwan does not have official ties with Japan.

Japan, Taiwan and China claim the islets and their surrounding waters, which are rich in fishery resources and potential natural gas deposits.

The Taiwanese boats on Monday carried national flags and banners that read "Trampling on human life," "Get out of Diaoyu Islands" and "Shame on Japan." (dpa)