The sound of gunfire early Saturday morning near the Downtown waterfront prompted officers to investigate the area, detaining five people before determining they were not involved in the shooting, police said.

Officers patrolling in the area of the 200 block of Golden Shore shortly after midnight Saturday heard what they thought sounded like gunfire, according to the LBPD.

Police searched the area for clues and located bullet casings and strike marks, indicating a shooting had taken place, but no injuries were reported, police said. A preliminary investigation suggested an unknown number of passengers in a van fired shots at un unknown target in the area, said police.

While they were collecting witness statements in the area, officers pulled over a vehicle near the Catalina Express terminal. The vehicle matched the description of the suspect vehicle based on eyewitness accounts, Richard Mejia, an LBPD spokesman, said.

Five people inside the vehicle were detained near the Catalina Express terminal. Mejia said no one was injured during the traffic stop and that officers determined that the people they detained was not involved in the shooting and they were released.