Pro-Russian separatists have seized the Donetsk offices of the regional state television network.
A crowd of around 400 people surrounded the building, shouting pro-Russian slogans and demanding a referendum. Protesters later left, but separatist guards remained at the doors.
When asked, one guard said they seized the building because it was "broadcasting misinformation."
A man who refused to give his name said the staff was still inside and would be sent home soon.
Separatists have already seized control of the city's regional governor's office and the city hall.