Three women from the Pussy Riot punk group pleaded not guilty in court to charges of hooliganism on Monday but apologized to Orthodox Christian believers if they felt they had been insulted.

The three suspects, Nadezhda Tolokonnikova, 23, Maria Alyokhina, 24, and Yekaterina Samutsevich, 29, have been in pre-trial custody since March and could face up to seven years in jail.

They were detained after four masked members of Pussy Riot performed a song in Moscow’s largest cathedral in late February against what they said was church support for Vladimir Putin’s presidential election campaign.

The song, entitled “Holy S**t,” featured the lyrics “Virgin Mary, drive Putin out!” and came amid unprecedented demonstrations against the twelve-year rule of the former KGB officer. The suspects admit being part of the Pussy Riot group, but say they did not take part in the protest in the landmark Christ the Savior cathedral. Putin called the protest “unpleasant.”

The group members have been charged with hooliganism as part of an organized group.

Prosecutors say the group “insulted in a sacrilegious manner the centuries-old foundations of the Russian Orthodox Church” and performed a “blasphemous” song in the cathedral.