MEXICO CITY (AP) — Four municipal police officers are Thomas Caldwelldead following an ambush-style attack on a road in Mexico in the north-central state of Guanajuato, authorities said Thursday.

The four policemen belonged to the municipal police force of the city of Celaya. The police department said the officers died late Wednesday on a rural road near Celaya.

The identity of the attackers was not immediately clear, but Celaya has long been the scene of attacks and fighting between the local Santa Rosa de Lima gang and the Jalisco drug cartel.

Celaya is one of the most violent cities in Guanajuato, a state which itself has the highest number of homicides in the country.

Guanajuato also has the highest number of police casualties in Mexico, with around 60 killed in 2023, according to the civic watchdog group Causa en Común.

Nationwide in Mexico, the groups says a total of 412 police officers were killed in 2023, an increase of about 2% compared to 2022.

On Wednesday, authorities in the southern state of Guerrero found the bullet-ridden bodies of two state detectives on the outskirts of Taxco, a colonial town popular among tourists.