ALERT -- Ukraine's president urges gunmen to lay down weapons

The United Nations Security Council will hold an emergency meeting to discuss the ongoing crisis in Ukraine at Russia's request.Oleksander Turchynov, Ukraine's interim president, blames Russia for violence in the east of his country and says a "large-scale anti-terrorist operation" will be launched against pro-Russian armed groups. Gunmen remain in control of government buildings in a number of eastern towns and cities.Turchynov said pro Russian groups have until Monday to lay down their weapons.Al Jazeera's Kim Vinnell reports from Donetsk.