More than 1,500 demonstrators marched through the violence-plagued border city of Tijuana on Saturday to protest the current of killings and kidnappings.

Among the protesters, doctors marched in white hospital garb to protest the general climate of violence and the kidnapping of a urologist in early November. The march was organized by the Civic Medical Committee.

Participants carried placards reading "God Save Us." Many dressed in white, in a gesture of peace, and delivered a petition at local government headquarters asking for greater anti-crime efforts.

But the killing continued in the Mexican border city across from San Diego.

Two people were shot to death Saturday at a Tijuana taco restaurant.

Prosecutors in Baja California state, where Tijuana is located, said two other people were wounded in the restaurant shooting, which apparently involved assault rifles.

Another man was shot to death at a pool hall, and two men were found shot to death on a street.

While prosecutors offered no immediate motive in the attacks, Tijuana has been hit by increasingly violent turf battles between rival drug cartels, in which heavily armed hitmen execute rivals on city streets and attack law enforcement officials.

The violence is affecting innocent bystanders, prompting the doctors to organize Saturday's march.

On Friday, gunmen attacked a state police convoy on a main boulevard in Tijuana, but prosecutors said no injuries were reported.

A man's decapitated head also was found Friday wrapped in duct tape beside a sign threatening members of a drug gang.