Four students have been injured in a drive-by shooting near Overbrook High School in Philadelphia, NBC News reports.

The victims were standing outside of a beauty salon near the school when a vehicle, identified as a silver Hyundai SUV, opened fire on them at approximately 11:30 a.m. on Wednesday. Philadelphia Police First Deputy Commissioner John Stanford said in a news conference the four students are two 15-year-old girls, and two 16-year-old boys. They were taken to a nearby hospital in a stable condition, authorities confirmed.

Police officers were in the area at the time, overseeing early school dismissal for Thanksgiving, and responded upon hearing the gunfire. No one inside the beauty salon, which was open at the time, was struck by the gunfire even though the building’s windows were shattered. The nearby high school was placed on lockdown for just over an hour around the time of the shooting. No arrests have been made, and it’s unclear if the attack was targeted or random.

“We are devastated how senseless gun violence continues to plague our city. Its impact extends to all students, staff, and school communities,” said the School District of Philadelphia. “The ongoing violence erases everyone’s sense of safety, especially during peak school times, such as arrival and dismissal periods.”

In a statement shared on Twitter, Philly mayor Jim Kenney said he is “heartbroken by yet another act of violence against students” in the city. “It's unconscionable that anyone would jeopardize young people by firing a gun near a school,” he added. “Our administration will work with @PHLschools to support the Overbrook High School community and with law enforcement to ensure the perpetrators are found and held accountable.”