MOSCOW -- 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!"

The three now face 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 she'd "pray for them." She then turned 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."