The Kremlin dismissed on Tuesday any criticism over the knife attack on a liberal radio journalist as work of a "madman" amid accusations the state fomented an atmosphere of hatred towards dissenters.

Tatyana Felgenhauer, a 32-year-old presenter, was attacked on Monday at the offices of the Echo of Moscow radio station by a man who claimed to have a "telepathic" connection with her.

Writing from her hospital bed at the Sklifosovsky Institute, Moscow's main emergency hospital, she said she would be fine and thanked her supporters.

"Breathing through a tube is even cool," she said in a hand-written note, a copy of which was posted on Twitter.

Felgenhauer underwent surgery on Monday but showed signs of improvements Tuesday, with doctors describing her condition as serious but stable.

"The actions of a madman are the actions of a madman," President Vladimir Putin's spokesman Dmitry Peskov told reporters.

"Trying to link them to anything is absolutely illogical and wrong," he said, expressing sympathy to the journalist and the radio station.

The suspect, identified as Boris Grits, a 48-year-old mentally unstable man, broke into the radio station's offices in central Moscow and lunged at the journalist with a knife after blinding a security guard with a spray.

Russian media, citing a relative of the suspect, said Grits appeared to suffer from delusions of persecution.

The assault comes after a string of attacks against prominent figures, the highest profile of which was Boris Nemtsov, an opposition leader gunned down on a bridge near the Kremlin in 2015.

- 'Atmosphere of hatred' -

Many commentators blamed the authorities for the attack, saying they had created an atmosphere in which such an assault became possible.

"Insanity does not appear (out of thin air)," Echo of Moscow editor Alexei Venediktov said, noting what he said was an "atmosphere of hatred" against journalists.

Political editor of top opposition newspaper Novaya Gazeta, Kirill Martynov, said state propaganda effectively sanctioned a witch hunt against dissenters.

"Calls to annihilate political opponents are becoming the norm," he said.

Felgenhauer featured in a smear documentary on the Rossiya 24 rolling news channel that claimed this month that the Echo of Moscow was in cahoots with foreign non-governmental organisations to undermine Russia.

"Tatyana has her own worldview, her opinion. Someone does not agree with her and criticises her in return too. In this case, we treat both points of view with respect," Peskov said.

"We are not part of this discussion."

Another top TV channel broadcasted a series this month about US secret agents in which an opposition female journalist has her throat slit.

"Grits's mental disorder amazingly dovetails with the party line," wrote outspoken commentator Yulia Latynina.

"Today the most important question is: was Grits simply a psycho or a psycho who has been used."

Latynina, who is also an Echo of Mosocw presenter, left Russia this year after attacks on her car and home.

An attack on top opposition politician Alexei Navalny this year left him nearly blind in one eye.

- 'Lost his mind' -

Moscow's Krasnopresnensky district court on Tuesday ruled that Grits should be placed under arrest until December 23, court spokesman Alexei Chernikov told AFP.

The Investigative Committee said Grits had been charged with attempted murder and would undergo a psychiatric evaluation.

The suspect's relative told mass-circulation newspaper Moskovsky Komsomolets that Grits, who is a national of both Russia and Israel, arrived in Russia more than a month ago and complained that the Echo of Moscow journalist had been stalking him.

The man said Grits looked jittery three days before the attack, adding he was surprised he had hurt the journalist.

"He never fought, he always ran away from problems," the unidentified man told the newspaper. "There is only one explanation: Boris has lost his mind."

Police on Monday released a video clip in which the suspect is saying he had known the journalist "telepathically" for years and that she sexually harassed him for the past week.

The Echo of Moscow, citing doctors, reported that Felgenhauer's vocal cords had not been damaged and the prognosis was "favourable"

Source: AFP