MOSCOW (Reuters) - Russia has detained two allies of jailed Kremlin foe Alexei Navalny, a prominent opposition activist said on Tuesday, adding that they could face extremism charges that carry lengthy prison terms.
Russian authorities have in recent months cracked down on groups affiliated with Navalny, 45, who is known as President Vladimir Putin's most vocal critic. He is serving two-and-a-half years in prison for parole violations related to a fraud case he says was politically motivated.
In June, a Russian court ruled that Navalny's anti-corruption foundation was 'extremist'.
Then, after his allies regrouped around a new network of organisations set up for Russia's parliamentary election in September, authorities started investigating campaign staffers on the same extremism charges.
On Tuesday, state investigators detained the former heads of provincial election headquarters in the Siberian cities of Tomsk and Irkutsk for questioning, Leonid Volkov, a Navalny ally living in exile, wrote on messaging app Telegram.
Volkov said he had tried to persuade both activists, Kseniya Fadeyeva and Zakhar Sarapulov, to leave Russia, as he and a number of other dissidents have done, but they refused.
The Investigative Committee, the state body tasked with investigating crimes and pressing charges, could not immediately be reached for comment on the case.
Navalny was flown to Germany last year for medical treatment after being poisoned in Siberia with what Western experts concluded was the military nerve agent Novichok.
The Russian government has denied it was behind the poisoning and rejected the experts' findings - which prompted a fresh wave of sanctions against Russia - and accused the West of a smear campaign against it.
(Reporting by Anton Zverev; Writing by Olzhas Auyezov; Editing by Gareth Jones)