In the second largest city, Kharkiv, the mayor - Hennady Kernes - was shot in the back as he was exercising. He's critically wounded.br br In Kostyantynivka (COST-YAN-TINIVKA), masked gunmen seized the city hall and police station, and distributed ribbons associated with the pro-Russia movement.br br Al Jazeera's Hoda Abdel Hamid is in Kostyantynivka.