Two members of the punk protest band Pussy Riot have filed a complaint at the European Court of Human Rights over Russia's refusal to register their prisoners' rights group.

Nadezhda Tolokonnikova and Maria Alyokhina told the Russian daily Vedomosti they believe the Justice Ministry's refusal to register their group, Zona Prava (Law Zone), was illegal and contradicted guarantees of free assembly and association. 

The report was published by Vedomosti on February 26 and confirmed by a website affiliated with Zona Prava, www.zona.media

In October, a court in Moscow ruled that Justice Ministry refusal to register Zona Prava was legal. 

Tolokonnikova and Alyokhina were convicted of hooliganism for bursting into Russia' main cathedral in 2012 and sang a "punk prayer" against Vladimir Putin.

They 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 ahead of the Sochi Olympics.