MEXICO CITY - Police have found the dismembered bodies of nine men in plastic bin bags in the back of a van in the western Mexican state of Guerrero, the latest in a wave of drug-related killings, authorities said Friday.

Fourteen other people were reported killed in other drug-related violence Thursday night and Friday, officials said.

The heads, body parts and torsos of the nine men were found late Thursday in a mountainous area of Guerrero. They had been stuffed into black plastic bags and left in a van.

Threats attributed to La Familia, a powerful drug cartel based in the neighbouring state of Michoacan, were scrawled on signs found with the bodies.

"La Familia doesn't kill innocent people. Those who die have to die," said one of the messages.

Guerrero is a major hub for drug trafficking and home to the resort of Acapulco, where police found the bodies of three more men in a van in a residential neighbourhood. A threatening message also was left with those bodies, the state prosecutor's office said.

Another male body was found dumped outside a cemetery near a small town in the same state, also with the same message, authorities said.

Elsewhere, attackers shot dead two men overnight in a bar in the central city of Cuernavaca, local authorities said in a statement.

Officials reported eight deaths Friday in the northern border state of Chihuahua, which is on major drug routes and at the epicentre of the country's drug attacks.

Violence has increased despite the deployment of more than 50,000 soldiers nationwide since late 2006 in a crackdown on organized crime.