An activity hosted by the US Embassy in Beijing on popular Chinese question-and-answer website zhihu.com has been halted by authorities, a source told the Global Times on Tuesday night.



The contents of the online activity, entitled "Discover the US," could not be found on the website on Wednesday. Neither the US Embassy nor zhihu.com could be reached for comment as of press time.



The source did not reveal a reason for the authorities' removal of the online discussion.



The activity, which was launched by the US Embassy in late April, invited guests including four US diplomats working in the embassy, a professor of political science and environmental law, a Fulbright scholar at Nankai University, a political blogger and a theater worker to answer Net users' questions.



Zhihu is China's biggest question-and-answer knowledge aggregation site and is similar to US-based site Quora.



The online activity has raised concern among some netizens about whether the embassy was using cultural exchange to push US ideology.



A WeChat account affiliated with the Communist Youth League Central Committee released an article on Tuesday that published some Net users' comments about the activity and cited President Xi Jinping's remarks on strengthening ideological work.



"If we do not go and occupy the publicity and ideology battlefield, others will occupy it," Xi said at a national conference on publicity and ideological work in August 2013.



The WeChat article highlighted several comments, including one stating, "The sudden appearance of the US diplomats on zhihu.com seems to have triggered a high-level battle in the field of public opinion." Another comment noted that, "These diplomats all display the bright side of life in the US."



Net user Laerhu's comment cited former US ambassador to China Jon Huntsman's remarks on using netizens and young Chinese people to "take China down," remarks that were also highlighted in the WeChat article.



Zhang Zhi'an, vice president of the School of Communication and Design at Sun Yat-sen University, told the Global Times on Wednesday that China can learn from the US Embassy's activity, since it is an effective and clever way to use popular social media to burnish the US image and expand its influence among the Chinese public.



"Discussions of the event showed that Chinese netizens have the ability to identify those propaganda measures," Jin Canrong, vice director of the School of International Studies at the Renmin University of China, told the Global Times, adding that China should act more confidently.



There were 43 questions listed on the activity's webpage, ranging from "how to get cheap Broadway tickets" to "what jobs election campaign advisors do after the end of the presidential election." More than 10 questions were about visa rules. The US Embassy runs more than 60 social media accounts in China, the Nandu Weekly said.



