State buildings in a number of towns have been occupied by pro-Russian gunmen, a move which Kiev says is an act of aggression from Moscow.
In Slovyansk, armed men have opened fire as they seized a police headquarters and security service building.
And in Donetsk, where they declared a people's republic last week, armed men have taken over a police headquarters.
Al Jazeera's Kim Vinnell reports from Donetsk.
Source: Al Jazeera