Zambian police are investigating claims that managers at a Chinese-run coal mine in the south of the country shot and wounded at least 11 miners.
Reports say the Chinese managers had opened fire on Friday because they felt threatened by miners who protested about their working conditions.
No-one has been charged so far after the shooting at the Collum mine.
China has invested heavily in the Zambian economy but this has led to some worker resentment.
In 2006, an opposition presidential candidate campaigned openly on an anti-foreigner platform and did well in areas where the Chinese presence was most visible.
"The workers were protesting against the poor working conditions when managers using shotguns started to shoot aimlessly, not in the air," Zambian police spokesman Ndandula Siamana told the AFP news agency.
"It's possible that the managers feared that they might be attacked but we shall ensure that the culprits are brought to book," he said.
The spokesman added that the injured Zambian miners were currently being treated at a hospital in the town of Sinazongwe.
The management of the Collum mine has so far made no public comment about the incident.
Last year China invested more than $400m (£250m) in Zambia's mining industry, and Chinese investments in the county are continuing to grow.