PHILADELPHIA (AP) — A student at the University of Oklahoma was temporarily suspended and police are investigating a threat against a Muslim student near the University of Michigan amid racially charged outbursts at schools and universities across the country following Donald Trump’s presidential election.

The Associated Press and other local media outlets identified several reports of racist incidents at schools since Tuesday, including a group chat that the Oklahoma student got involved with aimed at black freshmen at the University of Pennsylvania, Trump’s alma mater.

The chat contained “violent, racist and thoroughly disgusting images and messages,” and Penn is “appalled” its students were added to the GroupMe account,” UPenn President Amy Gutmann said. Gutmann said UPenn police have been working with the FBI. She earlier said officials had increased campus safety and were “reaching out to support the affected students.”

University of Oklahoma President David Boren in a statement said the student has been temporarily suspended as the school investigates further.

“It would appear this matter did not originate at the University of Oklahoma, but started elsewhere,” Boren said in a statement.

In Ann Arbor, Michigan, police are looking into a report of a man who threatened to set a Muslim student on fire with a lighter if she didn’t remove her hijab on Friday. The incident apparently happened near the University of Michigan campus, according to Ann Arbor police Sgt. Patrick Maguire. He added that the department is “investigating it actively … and soliciting information from anyone who may have witnessed anything.”

A crime alert issued by the university said the woman took off her hijab and left the area. Witnesses told police the man was white with an “unkempt appearance” and “intoxicated with slurred speech.”

The Michigan chapter of the Council on American-Islamic Relations called Saturday for the incident to be investigated as a hate crime, saying the “alleged attack is just the latest anti-Muslim incident reported since the election of Donald Trump as president.”

“Our nation’s leaders, and particularly President-elect Donald Trump, need to speak out forcefully against the wave of anti-Muslim incidents sweeping the country after Tuesday’s election,” said Dawud Walid, executive director of the Michigan chapter of the Council on American-Islamic Relations.

A racial backlash also unfolded after the election of Barack Obama, America’s first black president, in 2008. At the time, police documented alleged crimes, from vandalism and vague threats to at least one physical attack. Insults and taunts were delivered by adults, college students and even children.

Anti-Trump protests have taken place since the election in cities including Philadelphia, Atlanta, Chicago, Los Angeles, Portland, Oregon, and New York.