Sivasspor celebrates the beginning of the new season. It's a tradition in central anatolian region, people sacrifice somethings for beginning, opening or celebration of somethings. ( not for little jobs though )
Your team did a mistake by playing against the team of such a city with low mentality and paganic traditions. It's one of the cities I will never go or visit in any case ! Sivas is also a criminal with its history ( massacres against Alevis )
And by the way, I'm sure there are some provacateur people who can blame all of Turks and Turkish culture over this event, my message to them is that they should look at themselves first