NKANDABBWE, Zambia — Hundreds of angry coal miners pushed toward the locked gate at Shaft 3, shouting and cursing as they neared the mine’s Chinese managers, who understood neither the English nor the Tonga words of the mob. As the workers butted up against the fence, the bosses grew more fearful and finally two fired their shotguns.
The Zambian miners scrambled in terror. Bodies pivoted, jounced and stumbled. Boston Munakazela did not know he was hit until he suddenly fell over and saw the blood on his chest and arms. Vincent Chenjele was knocked off his bicycle with a hole ripped in his belly. Wisborn Simutombo, bleeding from his arms, legs and stomach, pleaded with friends to pull him to safety across the coal-dusted road.
“We weren’t going to hurt them, but maybe the Chinese didn’t understand that,” Mr. Simutombo, 25, said recently, displaying scars left by the spray of shotgun pellets. “They were quick to shoot us though, and in Zambia the Chinese can get away with anything.”

As in many other African nations, the Chinese are an enormous economic presence in this impoverished but mineral-rich country, and their treatment of local workers has become an explosive political issue, presenting an awkward balancing act for governments desperate for foreign investment. “We’re an economy in transition, and we can’t afford to lose the cow that gives us milk today,” said Labor Minister Austin Liato.