UFA, Russia -- A court in Russia's Bashkortostan region has extended pretrial detention for opposition politician Airat Dilmukhametov.
A court in the regional capital, Ufa, on April 29 ruled that Dilmukhametov must stay in pretrial detention until July 6.
Dilmukhametov was arrested on March 15 and charged with public calls to violate Russia's territorial integrity, a charge stemming from a video statement he made last year calling for the creation of a "real" federation in Russia with more autonomous rights given to ethnic republics and regions.
Dilmukhametov's lawyer, Aleksei Zakharov, told RFE/RL that the Federal Security Service (FSB) was working on new charges against his client.
According to Zakharov, the new pending charges against Dilmukhametov are public calls for extremism and support of terrorism.
Those charges are linked to Dilmukhametov's criticism of regional authorities for incarcerating several Bashkirs on charges of belonging to a banned Islamic group and his public statements in September 2018 about a conflict between local residents and workers from Chechnya in the village of Temas.
Zakharov said also that he was unaware of the specific details of the pending charges, adding that the court's ruling to prolong Dilmukhametov's pretrial detention will be appealed.
Dilmukhametov's supporters say the additional charges are being filed because his current charge is "weak" and investigators are trying to find additional accusations.
Dilmukhametov has maintained his innocence, saying all of the charges against him are politically motivated.
The Moscow-based human rights group Memorial has recognized Dilmukhametov as a prisoner of conscience.
Dilmukhametov's detention was also condemned by the Yabloko opposition party, the Congress of the Bashkir People, and the Congress of Kalmyk People.