A leading member of the Russian punk protest band Pussy Riot, Maria Alyokhina, has been briefly detained in Russian-occupied Crimea for the second time in two days.

An RFE/RL correspondent reported that police detained Alyokhina and local activist Aleksei Yefremov in a cafe in the Crimean city of Simferopol on February 27.

The move came after they were confronted by several men in traditional Cossack military uniforms who called themselves members of "Crimea's self-defense."

Human rights activists later said that Alyokhina was brought to a police station.

RFE/RL correspondent Anton Naumlyuk said that Alyokhina and Yefremov were taken to the police station to give statements about the incident in the cafe, and not because the protest they staged in support of jailed filmmaker Oleh Sentsov.

Naumlyuk said that Alyokhina subsequently left the police station.

On February 26, Alyokhina and two other Pussy Riot members, Olga Borisova and Aleksandr Sofeyev, were detained in different parts of Simferopol and taken to a local medical office for tests. It was not clear why the tests were performed.

The trio was later released, and for some time Borisova and Sofeyev's whereabouts were unknown.

But RFE/RL's Naumlyuk later reported that Borisova and Sofeyev had already returned to Moscow.

The trio had said it planned to stage a protest on the Ukrainian peninsula in support of Sentsov.

In August, Alyokhina and Borisova were detained and fined after staging a protest near the remote prison in Siberia where Sentsov is serving a 20-year prison sentence on terrorism charges that he and supporters say are groundless.

Sentsov is from Crimea, the Ukrainian region that Russia forcibly seized in March 2014.

Pussy Riot achieved prominence in 2012 after Alyokhina and fellow Pussy Riot performer Nadezhda Tolokonnikova were convicted of "hooliganism motivated by religious hatred" for a stunt in which band members burst into Moscow's Christ the Savior Cathedral and sang a "punk prayer" against then-Prime Minister Vladimir Putin, who was campaigning for his return to the presidency at the time.

Alyokhina and Tolokonnikova were close to the end of their two-year prison sentences when they were freed in December 2013, under an amnesty they dismissed as a propaganda stunt to improve Putin's image ahead of the 2014 Sochi Winter Olympics.

They have focused largely on fighting for the rights of prisoners since their release.