KIEV, Feb 18 (Reuters) - Ukraine's riot police advanced on Kiev's Independence Square, focal point of 12 weeks of unrest against President Viktor Yanukovich, on Tuesday after a day of violent clashes with anti-government protesters near the parliament building.
But, though there was some fighting intially with protesters on the tops of barricades, riot police stopped on the edge of the area where thousands of activists are gathered and did not advance on to the square.
State security forces gave protesters until 6 p.m. to end public disturbances or face "tough measures". It was not clear if this also meant ending the mass protest on Independence Square, known locally as the Maidan, where opposition activists have been camped since early December.
A working group under Yanukovich urged opposition leaders to intervene to stop an escalation of the conflict and the risk of it spiralling into "armed conflict".