Armed assailants opened fire on a sport utility vehicle the governor of Oaxaca state was driving Thursday, slightly injuring him and wounding two bodyguards.

Gov. Jose Murat (search) was released from a state-run hospital after being treated for minor injuries, but received a second threat while he was being attended by doctors, he said.

"They called to say that this time I survived, but next time they are going to kill me," Murat told a news conference in Oaxaca City (search), 220 miles southeast of Mexico City.

Murat said he was fine except for a blow to the head and a cut on his leg, and insisted "this type of threat is not going to stop us." He said he didn't observe much during the attack, because his bodyguards pulled him quickly to safety. One of those guards was in a coma, the governor said.

"This doesn't just affect Oaxaca, this affects Mexico," an angry Murat told reporters. "This is archaic, this is primitive, to want to kill someone."

Officials said the motive of the attack was unclear, but Murat, a possible contender for the presidency in 2006, had received death threats.

President Vicente Fox (search) called Murat to offer his support and condemned the attack in a news release, calling it the "gravest threat to our democracy."

Fox instructed federal officials to assist the state's investigation into the assault. More than half a dozen investigators from the federal attorney general's office were poring over evidence with members of Oaxaca state's investigative team Thursday night, said Jesus Perez, a spokesman for Oaxaca's attorney general's office.

Murat was driving to a meeting at Oaxaca City's famed Victoria Hotel when he was attacked, government spokesman Carlos Velasco said.

Perez said two people who live near the site of the shooting as well as three employees of a nearby business came forward to tell police what they saw and heard at the time of the attack.

Velasco said the governor had received nine death threats since he took office in 1998, although he refused to speculate on who was behind Thursday's attack. He told W Radio the investigation should take place "along political lines."

Between six and eight assailants were waiting in ambush for the governor, Oaxaca federal police commander Alberto Vera said. Investigators were looking for two trucks believed to have been driven by the attackers.

Two of the governor's bodyguards were wounded, said Dr. Rosalino Vasquez, director of the Oaxaca hospital where the governor was treated.

Investigators found about 20 shells from 9mm pistols and 10 bullet casings from Kalashnikov rifles near the governor's sport utility vehicle, said Ricardo Dorantes, chief of investigative police in Oaxaca.

Oaxaca, one of Mexico's most heavily Indian states, has been a hotbed of political disputes, guerrilla raids and drug production.

In 1996, a band of rebels of the Popular Revolutionary Army, or EPR, demanding sweeping political reforms, killed nine police and three civilians in a raid on police and military installations in the Oaxaca seaside resort town of Huatulco.

"We do have problems with land disputes in the state ... but there has been no guerrilla activity since the governor took office," said Perez, the state attorney general's office spokesman.

Velasco said Murat "had affected many interests, and gone after many rural strongmen" during his term.

The governor is considered a leading member of the PRI. Murat was among dissident governors fighting to change the direction of the PRI after it lost the presidency for the first time in 71 years to Fox in July 2000.

Shortly after Fox's historic election, Murat said police had discovered telephone taps and microphones at his offices and residence, and he hinted that PRI rivals in the federal government may have been involved.