Two people who were detained by police in Xian for protesting about chronic pollution have been released, said activists familiar with the incident yesterday. Feng Honglian, who goes by the nickname of “Wu Mian” on the internet, and Zhang Hui were summoned by police after they and a handful of citizens took part in a protest in front of the city government and in the bustling shopping district in Xian on Sunday afternoon, one activist said, who spoke on the condition of anonymity for fear of official reprisal. They were holding up sheets of paper that read: “Smog causes cancer, everyone suffers” and “Clean up the smog, the government is responsible”, photographs posted online showed. Zhang was taken away shortly after the protest ended and Feng was detained late Sunday, said Wu Gan, known on the internet by his nickname “the Butcher.” They were both released Monday afternoon, he said. After her release, Feng posted an audio message to her supporters, saying she was accused by police of “slandering the national leader” in a satirical picture that poked fun at President Xi Jinping’s slogan of ruling by law. But she added that it was the anti-smog protest that got her into trouble. “They were embarrassed to say directly it was our protest that was the problem,” said a transcript of the message circulated on the internet. A policeman who answered the phone at the Dianzicheng police station in Xian said he had no knowledge of the incident. The protest was likely prompted by an anonymous message that circulated online last week, which urged ordinary citizens to congregate on major city squares across the country last Sunday to protest about chronic pollution which it said caused fatal diseases. But it appeared to have failed to attract most people’s attention, with the incident in Xian being the only protest reported.