Separatist rebels in Donetsk have taken over the headquarters of regional television and ordered it to start broadcasting in Russian.
It is the latest move by armed militants who have proclaimed an independent “people’s republic” within the city in east Ukraine.
Around 400 demonstrators chanted “Russia! Russia!” and “ Referendum!” They want a vote like the one in Crimea that preceded Moscow’s annexation last month.
Meanwhile in Slovyansk one of eight European observers being detained by separatists has been released for health reasons. The man is said to be a Swedish national.
The other seven are still being held. They are in Ukraine to try to encourage compliance with the Geneva peace deal but the separatists seized them three days ago.
Elsewhere in Kharkiv pro and anti-Russian protesters including Ukrainian football fans have clashed. ..Police tried to keep the sides apart but several individuals wielding bats and flares attacked opponents leaving some badly injured.