CULIACAN, Mexico (AFP) — Twenty bodies, several of them decapitated, were found on a highway bridge in a part of Mexico where factions of the Sinaloa drug cartel are fighting each other, authorities said Monday.

Four headless corpses were found by the roadside while 16 bodies were discovered inside an abandoned vehicle, the Sinaloa state prosecutor’s office said.

Five human heads were found inside a bag at the scene.

Violence has soared in the northwestern state since the capture almost a year ago of cartel co-founder Ismael “El Mayo” Zambada.

The veteran drug trafficker claimed he was kidnapped in Mexico by a son of notorious druglord Joaquin “El Chapo” Guzman and flown to the United States in a private plane against his will.

The conflict, which has left more than 1,200 people dead according to official figures, pits gang members loyal to El Chapo and his sons against others aligned with Zambada.

Criminal violence, most of it linked to drug trafficking, has claimed around 480,000 lives in Mexico since 2006 and left more than 120,000 people missing.