Ten municipal police officers were arrested Saturday on suspicion of participating in the killing of 12 Mexican federal agents, officials said.

The arrested officers were on the police force in Arteaga, a city in the province of Michoacan in Southwestern Mexico, CNN reported. The bodies were found Tuesday along a roadway in Michoacan.

Three warning messages were found with the bodies. One read: "So that you come for another. We will be waiting for you here."

The officers can be held for as long as 40 days without formal charges.

At least 18 agents and two soldiers have been killed in the province in the past week.

The national response to drug-fueled violence has angered the local governor, Leonel Godoy Rangel. When President Felipe Calderon, who comes from Michoacan, sent 1,000 agents there, Rangel described the deployment as an occupation.