A deeply emotive documentary on air pollution by a well-known journalist was quickly praised by a top government official, but after it drew some 100 million views online over the weekend, censors stepped in to tamp down the buzz, according to several accounts. Produced by former state television broadcaster Chai Jing, “Under the Dome” is a bleak look at the state of the Middle Kingdom’s skies and an unhappy commentary on how government efforts to target the problem have failed. Ms. Chai decided to investigate pollution after the birth of her daughter, who was diagnosed with a benign tumor at birth and had to be swiftly operated upon. The film has dominated China’s social media following its release online Saturday, which prompted both praise and criticism. On Sunday, the newly appointed Environment Minister Chen Jining told reporters that he had personally thanked Ms. Chai for her efforts, and likened her film to Rachel Carson’s seminal 1962 work, “Silent Spring,” which helped spark the U.S. environmental movement. But Sunday night, China’s propaganda arm cautioned editors to stop focusing attention on the film, according to several journalists. One editor at a well-respected commercial daily said Monday that propaganda authorities instructed his paper to cease further reporting on the documentary and remove any existing articles about it from the paper’s home page and apps. Yang Jie contributed to this article. An expanded version of this report appears on WSJ.com.