Intense gunbattles broke out across the Mexican city of Culiacan on Thursday as heavily armed cartel fighters clashed with security forces who detained one of drug lord Joaquin "El Chapo" Guzman's sons, forcing them to release him.
Security Minister Alfonso Durazo said a patrol by the National Guard militarised police first came under attack from inside a house in the city, 600 kilometres north-west of the capital, Mexico City.
After entering the house, they found four men including Ovidio Guzman, who is accused of drug trafficking in the United States.
The patrol was quickly overpowered by cartel gunmen, however, and the decision was taken to withdraw to protect the lives of the National Guard and restore calm in the city, where gangsters had set up roadblocks and were firing heavy weapons, Mr Durazo said.
"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," the minister said.
Videos published on social media showed a scene resembling a war zone, with gunmen, some wearing black ski masks firing mounted machine guns from the the back of pickup trucks as vehicles burned. People could be seen running for cover as gunfire rattled around them. Drivers drove in reverse frantically to move away from the clashes. Some drivers rolled under their stationary cars for cover.
The chaos in Culiacan, long a stronghold for the Guzmans' Sinaloa cartel, will increase pressure on President Lopez Obrador, who took office in December promising to pacify a country weary after more than a decade of drug war clashes. Murders this year are set to be at a record high.
The scenes in Sinaloa follow the massacre of more than a dozen police in western Mexico earlier this week, and the killing of 14 suspected gangsters by the army a day later.
El Chapo led the Sinaloa cartel for decades, escaping from prison twice before being arrested and extradited to the United States. He was found guilty in a US court in February of smuggling tonnes 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.
The indictment gave Ovidio's age as 28, and said he had been involved in trafficking conspiracies since he was a teenager.
However, two other of El Chapo's sons – Ivan Archivaldo and Jesus Alfredo, known as "los Chapitos," or "the little Chapos" – and are believed to currently run the Sinaloa cartel together with Ismael "El Mayo" Zambada.
