MEXICO CITY (AP) — Mexican authorities on Friday announced the discovery of bodies and remains in the northwestern state of Sinaloa in an area of an ongoing search for 10 missing workers from a Canadian gold and silver mine.

The statement from the Mexican Attorney General’s Office did not specify how many bodies or sets of remains were found, but said that one of the bodies had the “characteristics of one of the people reported as missing.”

The office also reported the arrests of four people believed to be tied to the workers’ disappearances.

The Sinaloa state prosecutor’s office said the remains were found in the community of El Verde, in the municipality of Concordia, where the mine is located.

In the same area, the Navy reported the dismantling of 10 camps that had been used by cartel members.

The mountainous region is one of various points in the state where a turf war has played out for more than a year between two rival factions of the Sinaloa cartel.

On Jan. 28, mining company Vancouver-based Vizsla Silver reported the abduction of 10 people from its facilities. It said it had alerted authorities and its crisis management and security response teams were involved in the search.

The company did not immediately respond to an e-mailed request for comment late Friday.

The federal government increased the number of troops deployed to the state and launched an operation to find the workers.

Mines have been the target of organized crime on other occasions in Mexico, as cartels see opportunities to extort or even sell valuable ore themselves.