A former leader of a black student group in New Jersey has been sentenced to 90 days in jail for tweeting anonymous threats against fellow black college students.

Kayla McKelvey pleaded guilty in April to creating a false public alarm. A judge declined to admit her into a pretrial intervention program that would have let her avoid jail time.

McKelvey's sentence Friday in Union County also included five years' probation.

Prosecutors alleged the 25-year-old tweeted threats from a Kean University library because she wanted more people to attend a November 2015 rally on racial issues. She then returned to the rally to tell people about the threats.

The university increased security, and several law enforcement agencies including the U.S. Department of Homeland Security were alerted.