A bomb has killed at least two people, including a police officer, and injured 10 others at a rally in Ukraine's second city Kharkiv.

The march was one of several being held to mark a year since the Kiev uprising that led to the fall of pro-Russia leader Viktor Yanukovych.

Kharkiv lies outside the conflict zone in eastern Ukraine, where a ceasefire appears finally to be taking hold.

David Stern reports.