The Japan Coast Guard early Wednesday arrested the captain of a Chinese fishing vessel after his ship hit two Japan Coast Guard patrol boats on Tuesday inside Japanese territorial waters near the disputed Senkaku Islands in the East China Sea.

Because the ship was inside territorial waters, the Japanese Foreign Ministry on Tuesday lodged a protest with Chinese Ambassador to Japan Cheng Yonghua by phone. The Chinese Foreign Ministry, in turn, summoned Japanese Ambassador to China Uichiro Niwa on Wednesday to lodge a protest.

Some 40 Chinese activists staged a protest in front of the Japanese Embassy in Beijing on Wednesday. There may be more protests in China and Hong Kong. Both Tokyo and Beijing must prevent the latest incident from getting out of hand.