Zambia agreed on Monday to release 31 Chinese nationals it was detaining in the African country after Beijing's diplomatic efforts to help repatriate the individuals it claims were held through selective enforcement.

According to Red Star News, a Chinese online publication, Chinese embassy staffers said Zambia agreed to release the Chinese detainees after China's Ambassador to Zambia Yang Youming work-ed with Steven Kampyongo, the Zambian home affairs minister.

"Zambia agreed to release all the 31 Chinese nationals, and the Zambian government won't prosecute them. But all 31 have to leave Zambia today, with no exceptions," the report said.

The 31 Chinese have not been expelled and can return to Zambia in the future, it said, adding that the information still needs to be confirmed.

Zambia detained the Chinese nationals working for a Chinese company and accused them of illegal mining in the country's copper belt. But the authorities failed to provide strong proof of their crimes, the Foreign Ministry has said.

"The government has always asked Chinese companies and citizens to respect the laws of the countries where they operate and does not shield illegal action," Foreign Ministry spokeswoman Hua Chunying said at a regular news briefing on Monday.

"But China opposes selective law-enforcement actions against its citizens," she said.

She said the Chinese embassy sent a working group to urge Zambia to improve treatment of the detained.

Lin Songtian, the ministry's director-general of the Department of African Affairs, told a senior Zambian diplomat on Sunday that China understands and supports actions against illegal mining. However, Zambia had failed to provide strong proof of criminal activity by the 31 workers and held a pregnant woman and two malaria patients, Lin said.

China hoped Zambia would handle the incident according to the law appropriately and release the workers, Lin said.

The Zambian diplomat said his country cherishes its relations with China and will closely cooperate with China to properly handle the case.

He Wenping, a researcher at the Institute of West Asian and African Studies of the Chinese Academy of Social Sciences, said China has long assisted and supported Zambia and laid a solid foundation for a good working relationship between the two nations.

"For example, Beijing financed and built the Tazara Railway in the 1970s, which gave countries including Zambia access to a seaport" in Tanzania, she said.

Civil disputes in the mining industry are a new phenomenon between the two nations and they must be handled properly, she said.