Why did Hutus seek revenge against the Tutsis after the Belgians left the country in 1959?

The Split between Hutus and Tutsis arose not as a result of religious or cultural differences, but economic ones. "Hutus" were people who farmed crops, while "Tutsis" were people who tended livestock. Most Rwandans were Hutus. Gradually, these class divisions became seen as ethnic designations.

answer; belief perseverance;