Authorities in the southern Chinese province of Guangdong have detained at least 10 people following clashes between police and local residents protesting pollution from a nearby ironworks, ethnic minority residents of Daying village near Qingyuan city said on Wednesday. At least 10 people were injured after riot police were sent in to disperse a crowd of protesters who had blocked the entry to the Mingfeng Pipe Fittings Products factory for several days, members of the local Yao ethnic minority told RFA. "They behaved as if they were going after criminals," local resident Hai Shu said. A lot of people saw the police beating up an elderly guy over 60. "They pinned him to the floor like a criminal suspect, and he had a black eye and a bloody nose and face," Hai said. "Four of them dragged him into their vehicle and held him down with their boots; he wasn't allowed to move an inch," he said. Local residents say that pollution from the iron plant in nearby Yao'an township has gotten progressively worse since it opened three years ago. Environmental officials have visited the area to take samples, but no results have been made public, they said. "One village doesn't have enough water, so they have to use water from the river, and 50 to 60 people had diarrhea and vomiting," Hai said. "Also, all the duck eggs around here near the river are all very red inside." Hai said the villagers suspect the plant of sending toxic effluent into the river, just 10 meters away. "There is also horrible smoke that covers the sky, and we can often smell it in the evenings," Hai said. "It makes people dizzy; it must be poisonous." River 'severely polluted' A second local resident surnamed Liao said local people are convinced that the plant has left the nearby river severely polluted." I don't think it could pass environmental tests," Liao said. "If these plants passed the tests, then they wouldn't stick them out here in the back of beyond." An official who answered the phone at the Yao'an township government offices said the plant operates within legal guidelines. "The government takes this very seriously, and we are following this incident," the official said. "But I can't say much more because we haven't had the test results back yet." Repeated calls to the Mingfeng factory rang unanswered during office hours on Wednesday. Online information showed the 20,000 square-meter plant opened in 2009, and manufactures a range of cast-iron parts. A local resident surnamed Tan said the river water exudes a foul stench, and that nearby well water had also given people serious gastrointestinal symptoms. "This happened in the village next to ours," Tan said. "After they drank it, they had vomiting and diarrhea. When we take the rice we grow around here, our ducks, or any agricultural products to sell, people always ask if it's from this village, and then they don't want it," he said. "We all rely on what we can grow, so we have no way to exist here," Tan said. "We'll carry on protesting, even if the whole village ends up dead." 'Wait for results' An official who answered the phone at the environmental protection bureau in nearby Lianzhou city said the agency had taken samples of duck eggs from Yao'an for testing. "As for whether or not there is serious pollution in that area, we'll have to wait for the test results to come out," the official said. "We're not saying it's polluted, and we're not saying it's not polluted.You can always come here and talk to us in person." On Tuesday, thousands of angry protesters took to the streets of Neijiang city in the southwestern province of Sichuan amid growing popular anger over the leakage of toxic gas from a nearby coking plant, local residents told RFA. China has seen a huge increase in mass public protests sparked by worsening levels of air and water pollution, as well as public health scandals linked to heavy metal pollution from mining and industry. Protesters and environmental activists say there is widespread falsification of pollution testing and environmental impact assessments, making oversight of government-backed local industry nearly impossible. China has an exemplary body of environmental protection law that is rarely properly enforced in practice, environmental campaigners say.