The University of Southern California said it has canceled plans for a graduation speech by this year’s valedictorian, Asna Tabassum, who is Muslim. The school said the decision stemmed from security concerns, after several pro-Israeli groups objected to her social media posts supporting Palestinians.

The decision drew immediate criticism from the Los Angeles office of the Council on American-Islamic Relations, as well as from Ms. Tabassum, a biomedical engineering major.

“I am both…