According to local officials, the bodies of ten people were discovered on Thursday in the central Mexican state of Zacatecas, nine of them were hanged from a bridge in apparent gang-related killings.

According to a state ministry of public security officer who declined to be identified, the tenth body was discovered on a neighboring highway. The bodies were discovered in the Cuauhtemoc municipality, according to a statement from the state government.

According to the official, the killings were most likely the result of a feud between criminal gangs operating in the area. According to the local authorities, a “intense inquiry” was underway.

Gang-related violence in some parts of Mexico has intensified recently, including in the popular tourist zones of Quintana Roo state.

As of September, 21,495 people had died from gang-related violence this year, an average of almost 2,400 per month, according to the government.