Three men were killed and two were injured over the weekend in Pomona, California, and police are trying to connect the shootings.

45-year old Jose Cerda was riding a bicycle on Saturday night when a car pulled up alongside him and someone inside opened fire; he died at the scene. Just two hours later, 24-year old Isais Garcia Lopez and an 18-year-old unidentified male were walking in an alley near Orchid Lane when someone let loose several shots that killed Lopez and wounded the teen. Just hours after that, shots were fired on Canterbury Lane. When police arrived, they found a 29-year old man at the scene with a gunshot wound to his leg. The last victim was 29-year old Angel Bravo, who was walking to the store when he was shot several times in the chest. That shooting happened not long after the one that wounded the fourth victim.

The city has suffered a lot of gun violence in recent years, with two teenagers fatally shot in April in the same alley where Lopez was killed, and in March four young men were murdered in a series of incidents that police say were unrelated. A peace rally had been held earlier this weekend, with scared residents asking why no arrests have been made.

“No one’s been either arrested, or brought up for it, so there’s a lot of unanswered questions,” Pastor Chris Cotinola said.

As of now, authorities are conducting the investigation as if the shootings were unrelated, but say they are comparing notes throughout the department to see if there is a connection between any of the victims.