The Lisbon Maru was a cargo ship that the Japanese used to transport POWs at the height of World War II. In October 1942, while carrying 1,800 British prisoners off the coast of East China's Zhejiang province, the ship was torpedoed by a United States submarine.

The Japanese guards tried to lock the POWs in the holds, intending for them to go down with the ship, but some prisoners eventually broke out before the ship sank.

Having spotted the sinking ship, fishermen on nearby Dongji Island, in Zhoushan, Zhejiang province, went out on small boats to rescue the drowning British soldiers. More than 800 prisoners died in the incident, but around 380 were saved.

Wu Buwei, grandson of the late fisherman Wu Qisheng, recounted the heroic rescue during the commemoration.

"My grandfather was one of the main organizers of the rescue efforts … I was told of their story when I was a child," said Wu, 63. "Men and women, the old and the young, everyone in the village was mobilized. They rowed their small fishing boats out to carry the British soldiers ashore, and then clothed and fed the soldiers with fish, sweet potatoes – all that they had at home.

"Regardless of the danger of being found out by Japanese soldiers, my father and some others also escorted three British to a safe place, and had a very precious photo with the three British soldiers.

"I'm proud of the courage of my grandfather and people from Dongji. My descendants also like to hear me talk about this story – I'm very happy that this rescue has forged a special friendship between China and the UK."