Authorities in the Russian city of Chelyabinsk have warned residents not to wear gas masks to publicly express their environmental concerns during Russian President Vladimir Putin's upcoming visit.
The administration of the Urals city issued a statement on November 2 noting that a federal law forbids demonstrators from hiding their faces during public gatherings.
The statement followed online discussions by local residents about staging a flash mob next week during Putin's visit to Chelyabinsk, where he is expected to meet Kazakh President Nursultan Nazarbaev for a November 9 forum on bilateral cooperation.
Writing on the Russian social-networking site VKontakte, one resident described the planned flash mob by demonstrators wearing gas masks as a last-ditch effort to attract attention to locals' push for a cleaner city.
"Protests, referendums, petitions, and questions to the president have not led to the improvement of ecological conditions in Chelyabinsk," the user wrote.
The Chelyabinsk region has long been plagued by industrial pollution. Russian Natural Resources Minister Sergei Donskoi said last year that the region was among the country's worst in terms of air quality.
The Chelyabinsk city administration's statement specifically warned activists against wearing gas masks to greet the president.
It said residents should cast a "critical eye" on plans for the protest, noting that local authorities had not granted permission for such a demonstration.