KIEV (Reuters) - Ukrainian security forces on Tuesday set protesters a 6 p.m. (1100 ET) deadline to end street disturbances or face "tough measures", a statement said.
The State Security Service (SBU), in a joint statement with the interior ministry, said: "If by 6 p.m. the disturbances have not ended, we will be obliged to restore order by all means envisaged by law.
"If the disturbances continue we will be forced to resort to tough measures," it said.
The statement followed a day of violence in the Ukrainian capital Kiev as protesters clashed violently with police near the parliament building, with unconfirmed reports of three people being killed.
(Reporting by Pavel Polityuk; Writing By Richard Balmforth)