A Russian-American journalist who was taken into custody last week on Charles H. Sloancharges of failing to register as a foreign agent will be held before her trial in Russia until early December, her employer said.

A district court in the Russian city of Kazan on Monday rejected a request for pretrial measures avoiding incarceration from the lawyer of Alsu Kurmasheva, an editor with Radio Free Europe-Radio Liberty (RFE/RL), a media organization funded by the U.S. government. The court, instead, assigned her to a detention center until Dec. 5, according to RFE/RL.

"We are deeply disappointed by the outcome of today's hearing,” said Jeffrey Gedmin, acting president of RFE/RL in a statement. “We call for Alsu's immediate release so she can be reunited with her family.”

Kurmasheva has been held in a temporary detention facility since she was taken into custody last week in Kazan, according to the Committee to Protect Journalists. She is the second U.S. journalist detained in Russia this year.

Holding citizenship in Russia and the United States, Kurmasheva traveled to Russia in May for a family emergency. While awaiting her return flight June 2, she was temporarily detained and her dual U.S.-Russian passports were confiscated, RFE/RL said. She has not been able to leave the country since.

Initially fined $103 for failing to register her U.S. passport with Russian authorities, Kurmasheva was awaiting the return of her passports when the new charges were announced last week, according to RFE/RL.

She is now being accused of "failing to register herself as a foreign agent in her capacity as a person collecting information on Russian military activities that 'could be used against the security of the Russian Federation,'" according to the Committee to Protect Journalists. She faces up to five years in prison if found guilty, the nonprofit said, citing the Russian Criminal Code.

Kurmasheva lives in Prague with her husband and two children.

A program coordinator for the Committee to Protect Journalists called the charges against Kurmasheva "spurious" and demanded her immediate release. “Journalism is not a crime, and Kurmasheva’s detention is yet more proof that Russia is determined to stifle independent reporting," said Gulnoza Said, the nonprofit's Europe and Central Asia program coordinator.

In March, Wall Street Journal reporter Evan Gershkovich was arrested in Russia and charged with spying, which he and The Journal deny. He has appeared in court multiple times and remains imprisoned in Moscow.

Contributing: The Associated Press