Mexico’s plague of drug-gang related violence showed no sign of let-up on Christmas Day – in the western state of Michoacan six severed human heads were found.

According to authorities, they were discovered in Jiquilpan, a municipality near the state of Jalisco – a region that has become a battleground for competing drug gangs in recent years.

The six men are yet to be identified and their bodies have not been found.

Though a particularly grim discovery, authorities regularly find dismembered body parts across Mexico’s more violent states, as cartels bury their victims in hidden graves.

In the southern state of Guerrero, seven people were massacred as they gathered to celebrate Christmas in the municipality of Atoyac de Alvarez.

Gunmen entered a house and shot dead five men from the same family – three brothers, their father and their uncle. A married couple who had been invited to lunch with the family were also killed.

State security spokesman Roberto Alvarez Heredia said two of the seven killed were municipal police officers and one a state police officer. Initial reports suggested the gunmen had wanted to kill one person in a revenge attack but ended up killing seven people.

In Chihuahua state, authorities said nine people were killed during Christmas Day violence, according to AFP. Five of those were in Ciudad Juarez, including three women who showed signs of having been tortured.