23 bodies were found inside three vehicles in a central area of Guadalajara,

23 bodies were found inside three vehicles in a central area of Guadalajara, capital of the western Mexican state of Jalisco and host city of the recent Pan Am Games, local police sources confirmed on Thursday.

At around 6:00 a.m. local time (12:00 GMT) on Thursday, local police received a report that a person was hit near the monument of Millennium Arches. However, the police only found three abandoned trucks with 23 bodies when they arrived at the scene.

The arches stand nearly 1.5 km from the Expo Guadalajara events center, the site of both Pan Am Games and the Guadalajara International Book Fair, which will be inaugurated on Saturday and considered as one of the most important event in the Spanish- speaking world.

Local police said that a banner signed by the criminal groups Millennium Cartel and Los Zetas was found in one of the cars, which was seemed to be written by the slaughter but its content has not been disclosed.

Los Zetas Cartel is the second most powerful drug cartel in Mexico and considered by the U.S. Drug Enforcement Administration as the most violent drug cartel and paramilitary enforcement group in Mexico.

Jalisco Public Safety Minister Luis Carlos Najera told local media that the authorities were alerted to the discovery of the bodies Thursday morning and all the corpses were "bound and gagged. "

He said that the bodies have been taken to the Forensic Medical Service for official identification to determine those responsible for the killing and local police are collecting images of surveillance cameras near the sites to identify the suspects.

The tragedy came just a day after 16 charred bodies were found in two vehicles in the city of Culiacan of northwestern Sinaloa state.

It is a common practice among Mexican drug cartels to capture one or more people without ransom in return, and the victims would be found dead days later.

More than 45,000 people have been killed in drug-related violence in Mexico since President Felipe Calderon launched the " war against organized crimes" in 2006.