Seven plastic bags containing human remains have been found after they were dumped on the streets of a Mexican city.
A severed head was among the find along with a haunting message on blood-stained paper from a cartel.
The message reads: "This is a message from the Cartel Noreste.
"For the f *** ing filthy people from the Old School Las Zetas, let it be crystal clear that the CDN does not sell crystal meth.
"We are going after you filthy f *** ing people."
The note was accompanied by a list of names.
It was signed by the gang called Tropa del Infierno - translated as Hell Troop - a group of hitmen believed to be the armed wing of the dangerous Cartel Noreste - Northeast Cartel CDN.
The message was reportedly addressed to the Old School Las Zetas, another gang formed from the Las Zetas cartel.
They were found in a neighbourhood in the north of the city of Monterrey, in northeastern Mexico.
Mario Perez, a spokesman for the General Prosecution of the State, told local media that "a report was received about bags with human remains.
"When officers arrived they spotted seven black bags with a head and a back, as well as a poster with a message."
No arrests have been reported.
The two gangs have reportedly been fighting for control of Monterrey since the beginning of the year.
Noreste Cartel and its Tropa del Infierno are based in the border city of Nuevo Laredo, in the state of Tamaulipas, which recently suffered a wave of violence.
The Tropa del Infierno reportedly threatened citizens in the city not to "play the role of reporter".
