MOSCOW -- A well-known Russian radio journalist who was stabbed in the throat by an attacker has been operated on and transferred to an intensive care unit, her employer said Tuesday.

Tatyana Felgenhauer, a top host and deputy editor-in-chief at Ekho Moskvy, Russia's only independent news radio station, scribbled a letter to her colleagues from her hospital bed to thank them for their support.

"I will be fine," she wrote. "I had a good sleep for the first time in my 16 years on the radio."

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Felgenhauer spent hours in a medically induced coma following Monday's attack at the station's studios in central Moscow - the latest in a slew of assaults on journalists and opposition figures. Most have remained unsolved.

CCTV footage released by the radio station on Tuesday showed the attacker spraying gas into the face of a security guard in the reception area, ducking under the turnstile and running.

Police officers detain an unidentified man who reportedly stabbed journalist Tatyana Felgenhauer in the Ekho Moskvy (Echo of Moscow) radio station office in Moscow, Russia, on Monday, Oct. 23 2017. Vitaly Ruvinsky / AP

The Investigative Committee has identified the assailant as 48-year-old Boris Grits, who holds Russian and Israeli citizenship. After being apprehended, he told investigators he had been in "telepathic contact with Felgenhauer" for five years.

Grits was put in custody immediately after the attack. A Moscow court ordered his formal arrest Tuesday and said he should be kept in custody for two months pending an investigation.

While Ekho Moskvy is majority-owned by a media arm of the state-controlled Gazprom natural gas giant, its programs have often been critical of the government, angering many in Russian political and business circles. Its hosts and journalists have previously reported death threats.

State-owned media have long targeted Ekho Moskvy along with other rare independent media outlets for its critical reporting.

The state television channel Rossiya 24 put out a report two weeks ago that claimed that the station paid for "destabilizing society" ahead of Russia's presidential election in March.

Another popular Ekho Moskvy host, Yulia Latynina, fled Russia in September following a suspected arson attack on her car. After that attack, the Committee to Protect Journalists urged Russian authorities "to identify and prosecute those responsible for the attacks."

Latynina wrote in Tuesday's edition of Novaya Gazeta that despite the latest assailant's apparent mental troubles the attack seems to be a logical follow-up to increasingly militant rhetoric in the state media that described Ekho Mosvky journalists as enemies.

"Grits' mental disorder curiously matches the party line," Latynina said. "The attack on Felgenhauer falls neatly into the line of numerous attacks on independent journalists and opposition politicians that were met with impunity."

Russian President Vladimir Putin's spokesman, Dmitry Peskov, described the attack as the "action of a madman," rejecting claims of a link between the attack on Felgenhauer and state media criticism of the station.