Zambian miners killed a Chinese supervisor and seriously wounded another on Saturday in a pay dispute at the Collum coal mine, labour minister Fackson Shamenda said on Sunday.

Chinese companies have invested more than $1bn in Zambia's copper industry, but animosity towards them is growing as Zambian workers accuse firms of abuses and underpaying.

Workers at Collum, 325km (200 miles) south of the capital, Lusaka, attacked Chinese bosses, demanding wage rises in line with those stipulated by the government last month.

In July, Zambia raised minimum wages to 522,000 kwacha (£70) for maids and household servants and to 1.1m kwacha for shop workers without unions.

"We are yet to establish the exact circumstances, but the report I have is that one Chinese was killed and another injured as the workers demanded the new minimum wage," said Shamenda.

Two years ago, Zambian police charged two Chinese supervisors at Collum with attempted murder following the shooting of 13 miners in a pay dispute.

China, which is hungry for resources, is investing heavily in Africa, a supplier of oil and raw materials such as copper and uranium, but critics have warned that its companies are importing their poor track record on workers' rights.

In July, China's President Hu Jintao offered $20bn in loans to African countries over the next three years, double the amount it pledged in 2009.