Jan. 8 (UPI) -- At least 25 people were killed over a course of two days, including 12 murders in two hours, in Ciudad Juárez, the Mexican city that borders El Paso, Texas.
Officials said 15 people were killed Thursday and 10 were killed on Friday in the Mexican city, the El Paso Times reported.
Across the entire state of Chihuahua, 31 people were killed, including 18 in a single hour, the Mexican Daily News reported.
"We are busy and worried without a doubt. We have various interpretations of what happened and what is happening," Juárez Mayor Armando Cabada told reporters Friday.
All victims were killed with firearms. One of the victims was a former police officer and two men's bodies were left half-naked in a road with signs of torture.
No arrests have been reported. Officials are still investigating the murders.
Two days before the murder spree, Chihuahua Gov. Javier Corral told citizens that officials were going to combat crime in 2018.
We have decided to make 2018 a year of security for Chihuahua and Ciudad Juárez and we're going to do it by strengthening our coordination and also our police intelligence strategy, placing emphasis on recidivism and drug dealing," Corral said.
Last year saw 770 homicides in Juárez -- a significant increase from 543 the year before. But the city has seen far worse years, including more than 3,000 homicides in 2010, during the height of drug cartel violence in the area.
The rash of killings follows a jump in homicides in Juárez last year with more than 770 deaths, including more than 80 in December.