An investigation is underway after a Secret Service agent, assigned to protect Treasury Secretary Janet Yellen, discharged a weapon during a confrontation outside her home early Tuesday.

Around 1:30 a.m., the agent observed a sedan with multiple occupants attempting to open car doors along the street near Yellen’s residence, according to Secret Service spokesman Anthony Guglielmi.

A confrontation ensued, during which the agent fired their weapon. It remains unclear how many shots were fired, but the Secret Service reported no evidence of injuries.

The suspects fled the scene in the sedan, prompting a lookout alert to local law enforcement, the Associated Press has reported.

The D.C. Metropolitan Police Department is leading the investigation, with the case also set for review by the U.S. Attorney’s Office.

Written by B.C. Begley