UKRAINE Crisis 2014 -- Violence breaks out in Mariupol

Fighting has broken out between Ukrainian troops and separatists in the eastern city of Mariupol.The violence on Friday took place at police headquarters, which had been seized by a pro-Russian group.The building was set on fire and attempts are underway to contain the blaze.But Al Jazeera's Jonah Hull, reporting from Mariupol, says it is still unclear exactly what is happening outside the police headquarters.