Eastern Ganzhou city has ordered three rare earth mines to halt production by year-end, according to local mining authorities.

The city issued a notice telling three of its eight major rare earth producing counties to halt production by the end of this year, said Li Guoqing, director of the city's mining management bureau, on Monday.

The three counties are mining areas that are allowed to be exploited, Li said.

Fiscal revenue contributed by rare earth mining in these counties has dropped below 10 million yuan (1.56 million U.S. dollars) per year, Li said, adding that production at one of the three counties has already been suspended.

It is unknown when production will resume, as they have to wait for directives from the provincial government, Li said.

The notice also told the counties to set production quotas to rare earth mines to prevent over-exploitation.

Ganzhou, Jiangxi Province, produces nearly 40 percent of the country's ionic rare earths, while China produces more than 90 percent of the world's rare earth metals, which are widely used in the manufacture of an array of sophisticated products, such as electric car batteries, wind turbines and aerospace alloys; however, China's rare earth reserves only account for about one third of the world's total.

To control environmental damage and protect resources, China has announced various policies, such as suspending the issuance of new licenses for rare earth prospecting and mining, imposing production caps and export quotas, and implementing tougher environmental standards.