Several hundred pro-Russian demonstrators have gathered outside the building of Ukraine's state security service (SBU) in the eastern city of Donetsk to protest the detention of local pro-Russian leader Pavel Gubarev.
Some of the demonstrators have already been detained by police.
Gubarev has reportedly already been taken to Kyiv, according to RFE/RL correspondent Tom Balmforth, something that has further angered the crowd, who were reportedly chanting "Fascists!" at police surrounding the SBU building.
Gubarev, a Donetsk businessman, led protesters who seized the regional administration building in Donetsk and raised the Russian flag.
He has called himself the "people's governor" and demanded that local authorities cut ties with Kyiv.