A giant banner accusing five prominent Kremlin critics of betraying Russia was unfurled Friday from a building in Moscow.
Among those featured on the sign, which hung from the Dom Knigi bookshop on Novy Arbat, opposite the offices of liberal-leaning radio station Ekho Moskvy, were anti-corruption blogger Alexei Navalny, and opposition politicians Ilya Ponomaryov and Boris Nemtsov.
Musicians Andrei Makarevich and Yury Shevchuk also featured on the banner alongside two suit-wearing creatures with the same heads as the extraterrestrials from the 1979 sci-fi film "Alien."
Makarevich, from Soviet-era band Mashina Vremeni, and Shevchuk, leader of the DDT rock band, have both criticized Russia's annexation of the Black Sea Crimean peninsula via social media and personal blogs.
One of the creatures is holding a briefcase emblazoned with a white ribbon — a symbol synonymous with the 2011-2012 anti-Putin demonstrations in Moscow.
The banner, which was soon removed, was printed with the words "The fifth column, aliens among us."
"There have been many films made and books written about how aliens secretly take over the Earth. … So far we haven't met any real aliens. However, the 'fifth column' of national traitors has unfortunately become an undeniable reality," said Glavplakat.ru, an art collective that took responsibility for the banner, Ridus news agency reported.
Far from acting in the interests of Russia and its citizens, these so-called "aliens are serving the interests of a very different civilization," added the statement released by Glavplakat.
Glavplakat's website was inaccessible as of Friday afternoon.