A gunfight in the northwestern Mexican province of Sinaloa left 16 people dead, officials said, as infighting within drug kingpin Joaquin “El Chapo” Guzman’s powerful drug cartel spilled over into the streets.

The victims, who were heavily armed and wearing bullet-proof vests, died following a six-hour shootout near the town of Tepuche. Following the shootout, police seized 40 high-caliber weapons, 10 grenades, 24 vehicles and 36 000 rounds of ammunition.