BEIJING, June 5 (Reuters) - Zambia has detained 31 Chinese nationals for illegal mining in the African country's copper belt but has failed to provide strong proof of their crimes, a senior Chinese diplomat said as he lodged a complaint.
Lin Songtian, the Chinese Foreign Ministry's director-general for African affairs, told a Zambian diplomat in Beijing that China understands and supports actions to crack down on illegal mining, the ministry said in a statement late on Sunday.
However, Zambia had not only not provided strong proof of the crimes of the 31 detained but had also detained a pregnant woman and two others with malaria, Lin said.
"China expresses serious concern and resolute opposition to this," the ministry cited Lin as saying.
China hoped that Zambia could handle the incident appropriately and as soon as possible, and release those who are innocent, Lin said.
Chinese companies have invested more than $1 billion in copper-rich Zambia but there has been animosity, with some Zambian workers accusing firms of abuses and underpaying.
In 2012, Zambian miners killed a Chinese supervisor and seriously wounded another in a pay dispute at a coal mine.
Zambian police charged two Chinese supervisors at the same coal mine with attempted murder two years earlier after the shooting of 13 miners in a pay dispute.
Resource-hungry China is investing heavily in Africa, a supplier of oil and raw materials like copper and uranium, but critics have warned that its companies are taking with them their poor track record on workers' rights and environmental protection. (Reporting by Ben Blanchard; Editing by Paul Tait)