Milošević initially refused to acquiesce, claiming that no one had won a majority. The Yugoslav constitution called for a runoff between the top two candidates in the event that no candidate won more than 50% of the vote. Official results put Koštunica ahead of Milošević but at under 50 percent. The internationally financed CeSID claimed otherwise, though its story changed throughout the two weeks between 24 September and 5 October. This led to mass demonstrations in Belgrade on 5 October, known as the Bulldozer Revolution.