CIUDAD JUÁREZ, Mexico: The Mexican border city of Juarez saw a rash of violence on Thursday that left businesses burned and at least eight people dead, including a local radio presenter, authorities and witnesses said.

In the first incident, two inmates died and four others were wounded in a riot at a prison, according to a statement from the prosecutor for the state of Chihuahua, which includes Ciudad Juarez.

Local media attributed the riot to the Sinaloa cartel, whose former leader, Joaquin “El Chapo” Guzman, is currently serving a life sentence in the United States.

Later in the day, two women were killed and another person was wounded in an attack at a Juarez food shop. The shop and two other premises were also set on fire.

That evening, gunmen shot four radio station employees to death as they were taking part in a promotional event outside a pizzeria.

Employees who came to the scene identified the dead as the presenter, a manager and two other workers at the station, according to a witness.

“I deeply regret the loss of human lives in this atrocity against Ciudad Juarez,” Chihuahua Governor Maru Campos said on Twitter, adding that state and federal authorities had been deployed to restore order in the city of 1.5 million, which sits just across the border from El Paso, Texas.

The killings in Juarez came just two days after violence similarly flared in the states of Jalisco and Guanajuato, in the east and center of the country, respectively.

Following Thursday’s killings, several parts of Juarez were deserted, with some universities cancelling classes on Friday and the local business chamber calling on the government to do more to combat organized crime.