Another protester was detained by Croatia defender Dejan Lovren, who pushed a male protester until a steward arrived.
"Hello everyone from the Luzhniki field, it's great here," the group said on Twitter , and released a statement calling for the freeing of political prisoners, an end to "illegal arrests" of protesters and to "allow political competition" in Russia.
The group has since become something of an international symbol of punk anarchy. Pussy Riot had two members imprisoned for two years for prior protests in Russia.
Russia's Pussy Riot anarchists briefly disrupted the World Cup game between France and Croatia , sending four people dressed as police onto the field and stopping the game.
The group managed to evade the numerous stewards on the sidelines to get onto the pitch, where one made it to midfield and high-fived France forward Kylian Mbappe. The group claimed responsibility via Twitter and said the protest was a message to free political prisoners.