A shooter opened fire on a huge gathering in downtown Philadelphia, the largest city in the eastern U.S. state of Pennsylvania, killing at least three people and injuring more than ten others.

The incident occurred soon before midnight Saturday, according to local media station WPVI-TV, when officers on patrol heard many gunshots coming from South Street. Two males and a woman were among those slain, and all three were shot many times in the body.

According to Police Inspector D. F. Pace, a police officer arriving to the scene noticed a guy firing into a throng of people and subsequently shot at the suspect, however it is unclear if the shooter was injured.

“I’m sure there were hundreds of people simply enjoying South Street as they do every Saturday when this incident occurred,” Pace added.

The status of individuals who were hurt in the incident is unknown. Later Philadelphia police via twitter warned people to stay away from the area.