​​The deputy editor in chief for Russia's leading news radio station was stabbed Monday by an unknown attacker who burst into its studios — the latest of a string of attacks on journalists and opposition activists in Moscow.

The attacker broke into its studios of Ekho Moskvy (Echo of Moscow), which has often been described as Russia's only independent news radio station, and stabbed Tatyana Felgenhauer in the throat, editor in chief Alexei Venediktov said.

'He knew where he was going.' — Alexei Venediktov, Ekho Moskvy editor-in-chief

The man sprayed gas in the face of a security guard at the entrance to the office building on the ground floor and went up to the 14th floor, location of the station's studios.

"The man came here on purpose. He knew where he was going," Venediktov told reporters.

Felgenhauer, 32, underwent surgery at a hospital and was put into a medically induced coma as doctors determine the best course of treatment, he said.

The attacker, after being apprehended, told investigators he had been in "telepathic contact with Felgenhauer" for five years.

Ekho Moskvy's searing criticism has irked many in the Russian government, and its hosts and journalists have reported death threats previously.

Another popular Ekho Moskvy host, Yulia Latynina, fled Russia in September following a suspected arson attack on her car.

The spokesperson for the Russian Prosecutor General's Office described the attack as "outrageous" and said prosecutors will investigate it closely.

Moscow police said the attacker had a personal grudge against Felgenhauer. It released a brief video in which the attacker claimed she was "haunting" him.

State-owned media have long targeted Ekho Moskvy for its critical reporting.

Ekho Moskvy is owned by a holding company ultimately controlled by state-owned gas giant Gazprom. It does however, give air time to journalists and commentators who are fiercely critical of the Kremlin and its allies.

RUSSIA-NEWSPAPER/MURDERS

Journalist Yulia Latynina, seen here in Moscow in 2009, fled Russia last month after a suspected arson attack on her car. (Alexander Natruskin/Reuters)

The state television channel Rossiya 24 released a report two weeks ago that described the station as an "arm of the U.S. State Department" that gets paid for "destabilizing society" ahead of Russia's presidential election in March.

Columnist Oleg Kashin, who survived a brutal attack in 2010 that was never properly investigated, said on the Dozhd television station that Felgenhauer's "blood is on the hands of people from Rossiya 24, too."

Dmitry Muratov, editor in chief of the Novaya Gazeta newspaper, says the failure of Russian authorities to respond to the recurrent attacks and threats against independent journalists, activists and opposition leaders have made such attacks possible. 

Russia Journalist Attacked

An ambulance leaves the Ekho Moskvy office in Moscow on Monday. (Alexander Zemlianichenko/Associated Press)

With files from Reuters