original_query: What caused the large riot at the Maksimir stadium on 1 May 2010?
query: What caused the large riot at the Maksimir stadium in Zagreb, Croatia, on 1 May 2010?
answer: The riot at Zagreb's Maksimir stadium on May 1, 2010, was a clash between the Bad Blue Boys (Dinamo Zagreb's hooligans) and the police, resulting in numerous arrests and one critically injured police officer.  Post-match violence continued, with one Dinamo fan being shot by police.