Two members of the Russian punk collective Pussy Riot are on the run and have fled the country, the band said in a Twitter message on Sunday. Three other Pussy Rioters were sentenced to two years in prison this month for performing a “punk prayer” inside Moscow’s main Orthodox cathedral. The prayer asked the Virgin Mary to free the country from President Vladimir V. Putin. The case, especially the impassioned closing statements from the three women, caused a worldwide sensation. Nadezhda Tolokonnikova, 22, one of the convicted members, said the trial “shows this political system is afraid of truth.”