Local authorities released 21 demonstrators in a small city in southwest China on Wednesday, after protests over a proposed metals plant appeared to have ended, The Wall Street Journal reported. Six people remain in custody for participating in the protests in Shifang city in Sichuan province, according to a government statement. Tensions subsided after government officials canceled plans for the molybdnum copper plant Tuesday. Shares in Sichuan Hongda (600331.SHA), the company behind the US$1.64 billion plant, plummeted 9.2% Wednesday on the news that the plant was halted. Protestors, fearing adverse health and environmental affects from the plant, vandalized police vehicles and stormed government offices, authorities said. Information on the protests was widely dispersed on the internet with “Shifang” being the most-searched term on Sina’s microblogging service Weibo on Wednesday. Many on Weibo called for an investigation into police conduct during the protest.