An opposition protester on Red Square carrying a banner calling for the destruction of the Lubyanka was whisked off to a psychiatric hospital Sunday after refusing to talk to police.

Nadezhda Nizovkina, 26, and Vera Lavreshina unfurled banners reading “The Lubyanka must be destroyed” and “We are for the constitutional convention.”

Nizovkina is a member of the Buryatia branch of the Solidarity movement, and Lavreshina is part of the Buryatia branch of the unregistered opposition party The Other Russia.

The Lubyanka houses the headquarters of the Federal Security Service and was once a notorious prison.

Police followed Nizovkina and Lavreshina from the Central Elections Commission office, where the two had wanted to protest. But police prohibited them, Lavreshina told The Moscow Times on Monday.

When police tried to snatch the banners from their hands, the activists lay down on the ground to attract attention, Lavreshina said.

Several police officers then carried them to a police car and dropped them off at the Kitai-Gorod police station.

Both Nizovkina and Lavreshina refused to identify themselves. But Lavreshina answered police questions, while Nizovkina didn’t.

Police called a separate ambulance for each of the two. One ambulance took Nizovkina away, but a lawyer interceded on Lavreshina’s behalf.

She was left there and later released.

Nizovkina was delivered to Gannushkina Psychiatric Hospital at about 9 p.m., Oleg Trubnikov, a Left Front member told The Moscow Times.

On Monday, Moscow’s Preobrazhensky District Court ruled that Nizovkina’s hospitalization was legal, Trubnikov said, adding that he had found out from a deputy chief doctor of the hospital.

The hospital had not obtained a written court order, Trubnikov said.

An expert commission headed by Lev Ponomaryov, leader of the For Human Rights movement, planned to visit the hospital Monday to pursue Nizovkina’s release, Trubnikov said.

Nizovkina will remain at the hospital until her mother arrives from Buryatia to take her away, Radio Free Europe’s Russian service reported Monday. The hospital had not managed to get in touch with the mother as of Monday afternoon, officials said.

Andrei Naryshkin, deputy chief doctor of the hospital, refused to elaborate on why Nizovkina had not been released, citing patient confidentiality.

Lalita Darchiyeva, a court spokeswoman, told The Moscow Times that Nizovkina’s case “falls into the category of classified,” and could not be discussed.

Lavreshina was taken to the same hospital last week after another opposition protest in front of the Central Elections Commission.

She was released the next day after a board of doctors ruled she was sane.

Another person protesting on Red Square on Sunday, identified only as Medvedev from St. Petersburg, was detained for holding a banner that read “Bans are banned” but was released, Interfax reported.

Last year, Left Front activist Vladislav Ryazantsev was sent for a sanity check by Rostov-on-Don police two days ahead of a March 31 opposition rally he was supposed to lead.

He was eventually found sane, but only an hour before the rally.

Many rallies are held nationwide on the last day of every month with 31 days to draw attention to Article 31 of the Constitution, which guarantees freedom of assembly.

Doctors told Ryazantsev that authorities had asked them to diagnose him as insane.