On Thursday, a Mexican security force of about 30 was patrolling Culiacán, a known stronghold for one of Guzman's cartel syndicates, 770 miles northwest of Mexico City, when they were shot at from a house.
Security fought back and entered the house. Inside, they apprehended Joaquin "El Chapo" Guzman's son, 28-year-old Ovidio Guzman, along with three others. Although he's not the most well-known son, the younger Guzman is wanted in the US on drug trafficking charges.
Things escalated from there. The house was surrounded by cartel soldiers, who out-numbered the Mexican security forces.
Local media reported that the cartel were using what appeared to be sniper rifles and machine guns.
next slide will load in 15 secondsSkip AdSkip AdHeavy gunfire came from both sides, and went on for hours.
The streets of the Mexican city quickly resembled a war zone. During the chaotic afternoon and evening, prisoners managed to escape from the local prison. Video showed at least 20 prisoners making a run for it, according to Reuters.
The cartel soldiers also set up blockades.
And set cars and buses alight. It's a common tactic to make it harder for the security forces to maneuver during skirmishes.
Black smoke covered Culiacán's skies.
next slide will load in 15 secondsSkip AdSkip AdResidents ran for cover, as shots were heard through the streets, and fighting continued on into the night. People on social media shared videos of parents stopping their cars on the street and telling their children to stay down close to the ground.
Reuters reported that so far, two people had been confirmed dead, and 21 injured, according to Cristobal Castaneda, head of security in Sinaloa.
The Mexican security forces were forced to hand Guzman back to the cartel soldiers. Security Minister Alfonso Duranzo told Reuters that they had done so to save people's lives.
Violence has plagued Sinaloa this year. Earlier this week, more than a dozen police were killed in a massacre in Western Mexico, and a day later the army retaliated killing 14 suspected criminals.
And Falko Ernst, a senior analyst for International Crisis Group in Mexico, said releasing Guzman set a "dangerous precedent" and sent a message that the government wasn't in control.