Police detained several protesters outside a downtown Moscow court on Thursday ahead of the appearance of three members of the all-female punk group Pussy Riot, who could face lengthy jail sentences over an anti-Putin protest in Moscow's largest cathedral.

"Freedom for Pussy Riot," several dozen demonstrators chanted.

The court will decide whether to remand the suspects in custody until their trial, on an as yet uknown date, the band's lawyer, Nikolai Polozov, told RIA Novosti.

Prosecutors asked the court to prolong custody until June 24, in part to "ensure the safety" of the suspects.

Five members of Pussy Riot, clad in brightly-colored balaclavas, bowed and crossed themselves as they sang an acapella version of a song entitled "Holy Sh*t" at the cathedral in February. The lyrics included lines such as "Holy Mother, Blessed Virgin, chase Putin out!" The protest came amid the biggest demonstrations against President-elect Vladimir Putin’s rule since he first came to power in 2000.

Suspects Maria Alyokhina, Nadezhda Tolokonnikova and Yekaterina Samutsevich were detained in early and mid-March and face up to seven years in jail on hooliganism charges. They have been remanded in custody until the trial. All the suspects admit being members of the Pussy Riot collective, but deny taking part in the cathedral performance. Both Alyokhina and Tolokonnikova have small children.

"We expect the women to be freed today to return to their families," Polozov said.

"This is a mockery of a case, and it should be closed immediately."

There is an increased police presence outside the Tagansky district court.

Amnesty International recognized the suspects of prisoners of conscience earlier this month, and a number of public and Orthodox Church figures have called for their release.