A man wielding an ax attacked on Monday morning a Moscow judge who refused to release on bail three members of the all-female punk group Pussy Riot, the online newspaper Gazeta.ru reported.
The group's members face up to seven years over a protest song in February against President-elect Vladimir Putin at Moscow's largest cathedral .
The man, whose name was not given, entered Yelena Ivanova's office on the pretext of filing a complaint.
He was promptly detained after bailiffs heard screams coming from Ivanova's office.
It is not clear whether the attack was linked to the three women's detention.
In a ruling last week, they were retained in custody until June 24.
Prosecutors had asked the court to prolong custody to "ensure the safety" of the suspects. A lawyer for the group said last month death threats had been made against them and their children.
Pussy Riot said the performance was a response to Orthodox Church head Patriarch Kirill’s backing of Putin in the run-up to his landslide March 4 election victory. The patriarch called the 12 years of Putin's rule a "miracle of God" in a televised meeting.