WASHINGTON — Hate crimes against Muslim Americans and mosques across the United States have tripled in the wake of the terrorist attacks in Paris and San Bernardino, Calif., with dozens occurring within just a month, according to new data.

The spike includes assaults on hijab-wearing students; arsons and vandalism at mosques; and shootings and death threats at Islamic-owned businesses, an analysis by a California State University research group has found.

President Obama and civil rights leaders have warned about anecdotal evidence of a recent Muslim backlash, particularly in California. But the analysis is the first to document the rise, amid a crescendo of anti-Islamic statements from politicians.

“The terrorist attacks, coupled with the ubiquity of these anti-Muslim stereotypes seeping into the mainstream, have emboldened people to act upon this fear and anger,” said Brian Levin, a criminologist at California State University, San Bernardino.