MEXICO CITY (AP) — Mexico City police reported that a shootout between rival gangs left six people dead and four wounded.

The city prosecutor’s office said Sunday that the shooting occurred outside a business in a rough neighborhood on the city’s north side. Bullets fired in the fray hit nearby businesses as well.

Police said the assailants in the Saturday shootout drove up and opened fire on a group of people outside a food and drinks establishment in the northern borough of Azcapotzalco.

The victims appear to have returned fire, because the alleged assailants’ car had several bullet holes in it when police pulled it over later. A gun was found in the vehicle, and three people riding in the car were arrested.

Police said some of the victims had criminal records, and the newspaper El Universal reported the attackers told police they had been hired by the violent Jalisco cartel. The city prosecutors' office was not immediately available to confirm that version.

Mexico City officials have repeatedly denied that the big drug cartels operate openly in the capital, acknowledging only that they use the city as a shipment point for drugs. But it has become increasingly clear the Jalisco cartel, the country's fastest-growing and most violent gang, is intent on expanding into the city, as it has elsewhere.

On June 26, some two dozen gunmen ambushed an armored vehicle carrying Mexico City's police chief; the chief later said the Jalisco cartel was responsible for that attack.