New York City Mayor Zohran Mamdani is holding a press conference Monday morning after an explosive device was thrown at anti-Islam protesters outside Gracie Mansion over the weekend.

On Saturday, at least one pro-Islam counterprotester deployed an improvised explosive device while clashing with right-wing protesters. Authorities said the device could have caused “serious injury or death.” No injuries were reported. The counterprotester and another person were arrested promptly.