In August 1866, when four fleets including the Dingyuan of the Qing North Sea Fleet arrived in port in Nagasaki, sailors that landed entered into conflict with the Japanese police force, resulting in deaths on both sides (two deaths on the Japanese side and six deaths on the Qing side) (Nagasaki incident)
1886年8月には清の北洋艦隊のうち定遠など4隻の軍艦が長崎港に入港した際、上陸した水兵が日本の警官隊と衝突し、双方に死傷者を出す(死者日本側2名、清側8名)騒ぎ(長崎事件)となった。