Tabasco had been largely spared the drug-related violence affecting Veracruz and Tamaulipas states, to the north.

Eight people were initially killed in the late Tuesday attack in the city of Cardenas, but a ninth victim died of his wounds on Wednesday. Another badly injured person is being guarded by police at a hospital.

Some of the victims may have been customers waiting for their cars at the shop.

Police said in a statement no one has been arrested and a motive in the killings has not been determined.

Cardenas city authorities on Monday found the body of woman along with a message warning the residents to stay indoors after midnight.

Meanwhile, gunmen ambushed and killed three police officers Tuesday in a suburb of northern city of Monterrey.

Guadalupe city police said the officers were attacked with assault rifles and grenades.