Maria Alyokhina, 24, will serve the rest of her two-year term at a women's prison camp in Perm, a Siberian region notorious for hosting some of the Soviet Union's harshest camps. Nadezhda Tolokonnikova, 22, has been sent to Mordovia, a region that also hosts a high number of prisons.

"These are the harshest camps of all the possible choices," the band said via its Twitter account on Monday.

Alyokhina and Tolokonnikova were convicted of hooliganism motivated by religious hatred for performing an anti-Putin "punk anthem" in a Moscow cathedral in February. They argued that their conviction was part of a growing crackdown on free speech and political activism in Russia.

They are expected to serve the rest of their sentences, which end in March 2014, in the camps, where conditions are reportedly dire.

A third member, Yekaterina Samutsevich, was released earlier this month after being given a suspended sentence. Pussy Riot's supporters have argued that her release was designed to give the appearance of mercy from the authorities.

Confusion reigned on Monday as relatives and lawyers tried to assess exactly where the women were sent. Both Perm and Mordovia host several prison camps, some of which comprised the Soviet-era gulag system. Prison authorities declined to comment on the women's whereabouts.

Alyokhina and Tolokonnikova had petitioned to serve their sentences in Moscow, arguing that they wanted to be close to their children. Alyokhina has a five-year-old son named Filipp, while Tolokonnikova has a four-year-old daughter named Gera.