Four men have been shot to death in San Francisco, and a vehicle possibly linked to the shooting could be headed toward the Pacific Coast Highway, authorities said.

The victims had been killed around 10 p.m. in the Hayes Valley part of the city, and all of them were dead at the scene. No arrests have yet been made, according to the San Francisco Chronicle.

The four men had been sitting in a car on the corner of Laguna and Page streets when an individual shot them. The back window was shattered, but the windshield was intact.

San Francisco police said a possible suspect vehicle — a silver Scion — was headed toward Highway 101, with California Highway Patrol in pursuit.

Residents reported up to 15 shots in calls to 911, and the city’s gunfire-detection system, ShotSpotter, also alerted authorities. The bullets also struck a parked car.

A neighbor said the shots initially sounded like firecrackers, but “then we heard the police,” according to the report.

Officers blocked off the area with yellow crime scene tape and began talking to witnesses in the area. Neighbors gathered to look at the scene in hopes that the victims were not loved ones.

Last year, San Francisco reported 45 homicides.

The Pacific Coast Highway is a major north-south state highway that runs along most of the coastline along the state of California, stretching from northern California through the Bay Area and down to Los Angeles. It also runs concurrently with US 101 across the Golden Gate Bridge.