Eight people were killed in gun battles in a Mexican city in what has been described as a failed operation to detain the son of convicted cartel boss Joaquin “El Chapo” Guzman.
Mexican federal security officials say one civilian, one member of the National Guard, one prisoner and five attackers were killed in the Sinaloa state capital of Culiacan.
Authorities say at least 16 people were also wounded.
Officials said late on Thursday that troops had come under fire from a house while on patrol, and found Ovidio Guzman Lopez inside.
However they now say it was an operation specifically intended to arrest Guzman on a warrant issued by a judge for extradition to the US.
President Andres Manuel Lopez Obrador said the decision to cancel the arrest on Thursday had saved lives.
Security Minister Alfonso Durazo says a patrol by National Guard militarised police first came under attack from within a house in the city of Culiacan, 1200km northwest of Mexico City.
After entering the house on Thursday, they found four men, including Ovidio Guzman, who is accused of drug trafficking in the United States.
The patrol was quickly outmatched by cartel gunmen, however, and it was withdrawn to prevent lives being lost, the government said.
Simultaneously, fighters swarmed through the city, battling police and soldiers in broad daylight.
They torched vehicles and left at least one petrol station ablaze.
“The decision was taken to retreat from the house, without Guzman, to try to avoid more violence in the area and preserve the lives of our personnel and recover calm in the city,” Mr Durazo told Reuters.
The reaction to Guzman’s capture was on a scale rarely seen during Mexico’s long drug war, even after his more famous father’s arrests.
“El Chapo” Guzman led the Sinaloa cartel for decades, escaping from prison twice before being arrested and extradited to the United States, where he was found guilty in a US court in February of smuggling tons of drugs and sentenced to life in prison.
He is believed to have about 12 children including Ovidio. The US Department of Justice unveiled an indictment against Ovidio and another of the brothers in February, charging them with conspiracy to distribute cocaine, methamphetamine and marijuana in the United States.