The director of a Ukrainian-language library in Moscow was placed under house arrest on Monday by a Russian court that accused her of allowing public access to banned literature. The director, Natalia Sharina, could face as much as five years in prison for what Russian law enforcement agencies said was the dissemination of books by a Ukrainian nationalist writer, Dmytro Korchynsky, that are banned in Russia for promoting anti-Russian propaganda. Ms. Sharina denied the charges, saying the banned books were “planted during the searches,” a claim that was repeated by staff members. “Books cannot constitute extremism, because in my opinion extremism is an action,” she said in the courtroom, the Kommersant newspaper reported. Ms. Sharina’s lawyers have appealed the decision, the Interfax news agency said, and Human Rights Watch called for her immediate release in a statement.