MOSCOW (AP) — An activist from the Russian punk collective Pussy Riot says she has been banned from leaving the country.

Maria Alekhina said she was heading to Britain to attend a theater performance based on her book when border police turned her back Wednesday.

Russian authorities explained the move by claiming that Alekhina had failed to perform her community service. Alekhina was sentenced to 140 hours of community service for protests outside the Moscow headquarters of the Federal Security Service, the top KGB successor. In December, she unfurled a banner reading "Happy Birthday, Hangmen!" and in April she threw paper planes to protest the agency's demand to shut the messaging service Telegram.

Alekhina and Pussy Riot bandmate Nadezhda Tolokonnikova spent nearly two years in prison for a 2012 protest inside Moscow's Cathedral of Christ the Savior.