DURANGO, Mexico, July 28 (UPI) -- Eight severed human heads were discovered in four locations in the capital of the Mexican state of Durango, authorities said.
Officials were led to the first discovery of two heads in Durango City Tuesday by an anonymous phone call, El Siglo de Durango reported.
Police and military personnel closed off the area near a highway exit and began an investigation, the newspaper said.
Further anonymous calls led authorities to a six more heads.
All the victims were men believed to have been 25 to 30 years of age, the local prosecutor's office said.
The state of Durango has been the scene of clashes between rival drug cartels in recent months, BBC News reported.
Drug-related messages were found with two of the heads, but officials did not reveal the contents, El Siglo reported.