Federal authorities are investigating a device thrown near Gracie Mansion during a protest that was designed to be lethal, according to sources familiar with the probe. The homemade explosive emitted smoke after being tossed near the official residence of New York City's mayor during Saturday demonstrations. Police officers quickly approached as protesters scattered from the scene.

The investigation is being handled by federal agencies due to the device's deadly design and the target's significance. Gracie Mansion, located in Manhattan's Yorkville neighborhood along the East River, serves as the official mayoral residence. The incident occurred amid ongoing protests in the city, though specific motivations remain under investigation. Smoke from the device was captured in photographs by witnesses.

Law enforcement officials are treating the incident with heightened seriousness given the device's lethal intent and the symbolic target. The investigation involves multiple agencies coordinating to determine who constructed and deployed the explosive. Federal involvement suggests authorities view this as a potential threat to public officials rather than a typical protest-related incident.