At least five people, including three police officers, were killed and three others injured when a car exploded near a police station in Coahuayana, Michoacán, Mexico, on Saturday.

The explosion scattered human remains across the area and is under investigation by Mexico’s Attorney General’s Office.

Michoacán is a hotspot for drug cartel activity, including groups designated as terrorist organizations by the U.S., and criminal groups increasingly use explosives, though car bombs are uncommon.

The state’s community police, originally formed to fight cartels, have sometimes been infiltrated by criminal elements, CBS News has reported.

The violence occurs amid ongoing cartel conflicts over drug trafficking routes and extortion operations, with local leaders and activists, such as recently killed lime grower Bernardo Bravo, frequently targeted for opposing organized crime.