(CNN) -- A former Mexican senator was reported missing on Saturday, Mexico's attorney general's office said.





The case has rocked Mexico, with President Felipe Calderon saying he is closely monitoring the investigation into the disappearance of the former official, Diego Fernandez de Cevallos Ramos.





The attorney general of the state where Fernandez de Cevallos was reported missing said that authorities have no clues as to his whereabouts.





Fernandez de Cevallos was last seen on the ranch of his home in Pedro Escobedo, in central Mexico's state of Queretaro, the country's official Notimex news agency reported.





The attorney general's office said that Fernandez de Cevallos' vehicle was located on his ranch and that "in the place where the car was located, some of his belongings were found and there were traces of violence."





Queretaro attorney Arsenio Duran said the former legislator had arrived alone at his La Cabana ranch, as he usually did, at approximately 11 p.m. Friday (midnight ET Saturday) and that it was presumed that he was kidnapped in the driveway of his property, Notimex reported.





Duran said that around 7 a.m. Saturday (8 a.m. ET) relatives of the former legislator noticed that the door to his truck was open, Notimex reported. Outside the vehicle were discarded glasses, pens and scissors; inside were traces of blood.





The federal attorney general's office has declined to call the case a kidnapping.





Queretaro authorities are investigating the case, the attorney general's office said.





A statement on the Mexican president's website said that Calderon "from the first hours of the morning, has been in constant communication with the attorney general and with the secretaries of Interior and Public Security," about the investigation.





The statement said that Calderon has "communicated with one of the two children of Fernandez de Cevallos, who is facing this difficult situation with integrity, to offer his solidarity and the necessary backing to successfully locate Fernandez de Cevallos."





The missing legislator was a senator from PAN, Mexico's National Action Party, and is a former presidential candidate. The statement on Calderon's website called Fernandez de Cevallos "a key politician in the Mexican democratic transition."





CNN's Esprit Smith contributed to this report.
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on the ranch of his home in Pedro Escobedo, some of his belongings Diego Fernandez de Cevallos Ramos. some of his belongings discarded glasses, pens on the ranch of his home in Pedro Escobedo, traces of blood.
question: Where was the ex-Senator last seen?, answer: on the ranch of his home in Pedro Escobedo, | question: What were found inside the ex-Senator's car ?, answer: some of his belongings | question: Who is missing?, answer: Diego Fernandez de Cevallos Ramos. | question: What was found inside  ex-Senator's car?, answer: some of his belongings | question: What was found outside the ex-Senators car?, answer: discarded glasses, pens | question: Where was de Cevallos Ramos last seen?, answer: on the ranch of his home in Pedro Escobedo, | question: What was found inside the ex-Senator's car?, answer: traces of blood.