Amnesty International urged Croatian authorities on Wednesday to release Aysoltan Niyazova, a Russian activist originally from Turkmenistan who joined the tour of the famous Russian band Pussy Riot.

Niyazova was arrested upon entering Croatia from Slovenia on an Interpol warrant and now faces possible extradition to Turkmenistan, for alleged embezzlement. She was detained in Zagreb on Monday.

“Croatian authorities know that Aysoltan Niyazova’s activism would put her at great risk of suffering serious abuse … should she be extradited to Turkmenistan,” Julia Hall, the Amnesty International deputy director for Europe, said in a statement.

“The authorities in Zagreb must refuse Turkmenistan’s request for … Niyazov’s extradition and immediately release her from detention,” Hall said.

She said the rights group had documented many cases of Turkmen authorities pressing charges based on fabricated or unreliable evidence.