President Felipe Calderon has ordered a massive manhunt to find a missing politician he described as a "personal friend" who may be the most prominent kidnap victim yet in Mexico's raging drug wars.

Diego Fernandez de Cevallos, who ran for president in 1994 representing the ruling conservative National Action Party (PAN), disappeared late Friday, prompting authorities to launch an investigation.

A vehicle belonging to Fernandez de Cevallos, 69, was found at his ranch near the town of Queretaro bearing "signs of violence," the prosecutor's office said, although officials had no other firm evidence of a kidnapping.

Authorities were searching Sunday for the 69-year-old lawmaker across the states of Mexico, Queretaro, Hidalgo and Guanajuato.

Prosecutors said he had been reported missing from his ranch and that his Hummer all-terrain-vehicle was found abandoned, along with some personal items and bloodstained scissors.

The federal government is acting very closely with local authorities to try to locate Fernandez de Cevallos, President Felipe Calderon said from Spain where he was on a visit.

Fernandez de Cevallos "is a very prominent Mexican, a key politician of the transition," Calderon added, as well as a "personal friend."

He said the politician's children were being strong, following their father's example.

There were no significant leads in the case as of midday Sunday, a spokesman for the prosecutor's office said.

Many media were stunned to see the uncertainty and fear of everyday life in areas hard hit by violence reach the highest echelon of Mexican political circles.

The leading daily La Jornada said the disappearance "injects new uncertainty and uneasiness into the country's social and political panorama."

It was not immediately known if there was any political motive behind the disappearance. The former presidential candidate now is partner in a law firm with Interior Minister Fernando Gomez Mont.

Fernandez de Cevallos finished second in the 1994 presidential election, losing out to former president Ernesto Zedillo of the Institutional Revolutionary Party (PRI).

Mexico City Mayor Marcelo Ebrard offered "any assistance that the authorities might need" to help track down Fernandez de Cevallos.

Vicente Fox, a member of the PAN who was Mexico's president between 2000 and 2006, expressed the concern of many over one of the country's larger-than-life political figures.

"We still don't know exactly what happened, but I greatly care for him and hope that he is all right," Fox told the daily Reforma newspaper.

Violent attacks have exploded across Mexico since Calderon launched a military crackdown on organized crime when he took office at the end of 2006. More than 22,700 people have died in the spiraling drug violence.

- AFP