Worsening air pollution in Chengdu, the capital city of Sichuan province, kindled calls for a mass protest on social media on Saturday but the smouldering unrest was extinguished before it began. Tianfu Square, the traffic and business hub of the city that is home to the famous panda breeding reserve, was empty on Saturday, when it would normally be bustling with tourists and local shoppers. Staff at nearby restaurants told the South China Morning Post that local police had blockaded the main access roads to the square, not allowing cars or pedestrians to pass. Earlier in the day, multiple posts on social media had called for people to protest at the square, but the posts were quickly deleted on Weibo, China’s version of Twitter. The microblog operator issued a statement that the posts were “false rumours”. A staff member who answered the phone at the nearby police station confirmed the blockades but refused to give a reason and declined to be identified. “It is a coordinated action upon the order of superiors, and it could last two or three days,” he said. No official explanation has yet been provided for the blockade and phone calls to the city government’s information office went unanswered. China tops world for air pollution and carbon emissions, officials admit Chengdu, which has a population of 15 million, issued a yellow alert for air pollution on December 3, the second-lowest level in a four-tier system. The alert has remained in place for the past week and pictures of mask-wearing residents and visitors to the city have spread over China’s social networking sites, with many locals demanding an immediate solution. A combination of fog and smog also shut down the Chengdu Shuangliu International Airport for 10 hours on December 4, delaying more than 100 flights, and a further 116 flights were cancelled on Thursday. “Chengdu is at the centre of the Sichuan Basin, which means it’s harder than elsewhere for pollutants to dissipate,” said Ma Jun, director of the Institute of Public and Environmental Affairs, an NGO that monitors pollution in China. “The smog is largely a result of local discharge.” Many locals blame the Pengzhou petrochemical project, which produces hazardous products like paraxylene, for much of the problem, and the plant was a target of some of the online calls to protest. The municipal government released a list of 80 local polluting plants, including steel, cement and papermaking firms, late on Friday to call for public supervision, in an apparent bid to ease local anger. How China’s quick blue-sky fixes make pollution worse “It is a small step forward, but more data such as the discharge of volatile organic compounds and real-time data should be released for the public to better judge the real pollution levels,” Ma said. “They are required by the Environmental Protection Law and the Air Pollution Prevention (and Control) Law.” The Pengzhou petrochemical plant is on that list. The project triggered wide criticism during its preparation stage and fierce local protests when construction of the plant began in 2013. The plant, owned by China’s largest oil refinery China National Petroleum Corp, is only 40 kilometres from the downtown area. Similar mass protests against petrochemical projects have also taken place in the cities of Xiamen, Fujian province; Dalian, Liaoning province, Ningbo, Zhejiang province; and Maoming, Guangdong province in the past decade.