The Ottawa Police Service is seeking witnesses to an act of hate-motivated vandalism in downtown Ottawa. Police say officers were called to the 300 block of Rideau Street, near Nelson Street, on reports of graffiti containing a racial slur on a mural. The Hate and Bias Crime Unit is leading the investigation. Anyone who witnessed the incident or has information that may assist investigators is asked to contact the Hate and Bias Crime Unit at 613-236-1222, extension 2015. Police say arrangements have been made to remove the graffiti.