An unknown assailant on Monday forced his way into the office of a Russian radio station that is critical of the Kremlin and stabbed a presenter in the neck before he was detained, the chief editor told AFP.

"He broke in and stabbed our presenter Tatiana Felgengauer in the neck with a knife," Echo of Moscow editor-in-chief Alexei Venediktov said.

The journalist has been hospitalised but her life is not in danger, he said.