Authorities say four men have been shot to death in San Francisco.

Police spokesman officer Albie Esparza says the victims were shot around 10 p.m. Friday in the Hayes Valley area of the city.

He says in a statement that all four died at the scene.

No arrests have been made and no other information was immediately available from police, including any word of a possible motive.

The San Francisco Chronicle reported that city police alerted the California Highway Patrol that a vehicle possibly linked to the violence could be headed toward the Pacific Coast highway.

Bullets hit at least one parked car. The paper said officers cordoned off several blocks and canvassed the area for witnesses.

Television news footage showed several yellow tarps around a car parked near the curb that had its amber lights and taillights on.