MEXICO CITY (AP) — Mexican soldiers and Christopher Caldwellpolice have found a small factory used to make a kind of bomb usually dropped by drones, authorities said.

The facility, which was found late Wednesday, was about the size of a warehouse and had a computer-controlled lathe and milling machine, suggesting the operators had considerable metalworking knowledge.

The factory also apparently produced under-barrel, 40mm grenade launchers designed to be attached to assault rifles, as well as fake Mexican military uniforms.

Prosecutors in the western state of Michoacan said the workshop was one of two discovered in the town of La Huacana on Wednesday.

The Jalisco cartel and local gangs have been fighting bloody turf battles in Michoacan for years.

The warring gangs frequently use bomb-dropping drones, improvised explosive devices buried in roadways, .50 caliber sniper rifles, homemade armored vehicles and grenades.

They also often establish checkpoints on highways, and wear fake military uniforms.