MOSCOW (AP) -- Madonna has expressed support for the jailed members of Russian punk band Pussy Riot by donning a ski mask and scrawling the group's name on her back.

In March, two weeks before Vladimir Putin won Russia's presidency for the third time, members of the female band high-kicked and danced in Moscow's main cathedral, singing "Virgin Mary, drive Putin away!"

Russian Prosecutors Ask For 3 Year Sentence For Pussy Riot's Anti-Putin Protest

The three now face seven years in jail in a case that has outraged human rights groups.

Madonna voiced support for Pussy Riot at a Tuesday night concert in Moscow, saying the band had "done something courageous, I think they have paid the price for this act and I pray for their freedom." She later exposed her bare back, which had "Pussy Riot" written on it, to the audience and put on the black mask, the band's symbol.

She went on to sing her 1990s hit, "Human Nature."

Pussy Riot, Russian Anti-Putin Punk Rock Band, Reject Hooliganism Charges

Earlier in the day (Aug. 7), the U.S. Embassy in Moscow and the U.S. Consulate General in St. Petersburg issued a warning for U.S. citizens in Russia planning to attend Madonna's concerts in Moscow or in St. Petersburg (Aug. 9). The information has been shared with Russian authorities, who have indicated they will add increased security to the events.

Full Statement From the U.S. Embassy:

U.S. Embassy Moscow and U.S. Consulate General St. Petersburg

SECURITY MESSAGE FOR U.S. CITIZENS:
MADONNA CONCERTS

August 7, 2012

This is to alert U.S. citizens in Russia who are planning to attend the Madonna concerts in Moscow on Tuesday, August 7, or in St. Petersburg on Thursday, August 9, that the U.S. Consulate General in St. Petersburg has received information regarding a threat of physical violence against spectators and performers at the St. Petersburg concert on August 9. The U.S. Embassy in Moscow and the U.S. Consulate General in St. Petersburg have shared the information with appropriate Russian law enforcement authorities. Russian authorities have indicated to the Embassy that they are taking appropriate measures in light of this information. While we expect that enhanced security measures will be put in place at both concerts, U.S. citizens are reminded to remain vigilant regarding their personal security, and to be aware of their surroundings at all times, especially in crowded areas.