Shots fired in Ukraine's port city of Mariupol.<br/> <br />Government forces took back the city hall from pro-Russian separatists Thursday.<br/> <br />One man was reported injured.<br/> <br />Control of the building exchanged hands several times this week, as east Ukraine moves towards a Sunday referendum on independence.<br/> <br />Separatists voted unanimously Thursday to move ahead with the vote as planned.<br/> <br />They defied a call by Russian President Vladimir Putin the day before to postpone the vote, and to give dialogue with the central government a try.<br/> <br />(SOUNDBITE) (Russian) LEADER OF SELF-PROCLAIMED 'PEOPLE'S REPUBLIC OF DONETSK', DENIS PUSHILIN, SAYING:<br/> <br />"The decision NOT to postpone the referendum was passed 100 percent. The referendum will be held on May 11."<br/> <br />Residents of rebel-held areas were stunned by Putin's remarks.<br/> <br />(SOUNDBITE) (Russian) PRESS OFFICER OF THE 'ARMY OF THE SOUTH EAST' SEPARATIST MOVEMENT, NIKOLA NIKITIN, SAYING:<br/> <br />"People want it to be held, peopl
