Sansha city in South China's Hainan province, the country's southernmost city, has banned fishing and tourism in and around the world's deepest blue hole as part of its efforts to protect the maritime environment in the South China Sea.

Organizations and individuals are forbidden from the activities in Longdong - known as "Dragon Hole" - or within 1 nautical mile of the blue hole, according to a notice issued by the management committee of the Yongle Islands in Sansha.

Other activities concerning the blue hole, such as scientific expeditions and environmental protection programs must be approved by the government, according to the notice.