It’s been a day now since three armed assailants in the Honduran city of San Pedro Sula burst into a women’s shoe factory with assault rifles. When the shooting stopped, 18 people lay dead or dying.

Initial blame fell on rivalries between street gangs, the feared Mara Salvatrucha and the equally violent 18th Street gang, both of which have roots in Los Angeles and operate through much of Central America.

But on a deeper level, the attack is a reflection of how Mexican-style violence is moving south. The gangs of Central America are subcontracting out to the narcotics cartels of Mexico and adopting their violent tactics.

“Yesterday’s massacre is the kind that takes place in some Mexican states, where drug trafficking and hired killings are the rule. But the massacre yesterday occurred on a main street in San Pedro Sula,” the local La Prensa newspaper said, “and it stunned a nation that hasn’t seen this much bloodshed in one place in many years.”

The assailants in the attack used AK-47 assault rifles, a favorite of the Mexican cartels as well. In Mexico, the rifles are called “ram’s horns” because of the curved ammo chamber.

The cause of the slaughter isn’t clear. Honduran papers say the 18th Street gang controls the neighborhood around the factory, where a lot of small-scale drug dealing takes place. The owner of the factory said none of his workers wore the facial and neck tattoos common among gang members. Forensic workers found no drugs or weapons in the factory after the shooting.