Hate crimes in nine U.S. metropolitan areas rose more than 20 percent last year, fueled by inflamed passions during the presidential campaign and more willingness for victims to step forward, a leading hate crimes researcher said on Monday.

Bias crimes appeared to increase in some cities following the Nov. 8 election of President Donald Trump, a trend that has extended into this year with a wave of bomb threats and desecrations at synagogues and Jewish cemeteries, according to California researcher Brian Levin.

The White House could not be reached immediately for comment on the research.