U.S. Ambassador to Mexico Earl Anthony Wayne (L) and Mexico's President Felipe Calderon sit together during an event in Mexico City August 28, 2012. Calderon on Tuesday promised justice for two U.S. agents as new details emerged on how they were allegedly shot at by federal police officers in plain clothes while heading to a Mexican marine base. Speaking alongside Wayne, Calderon said the incident should not dampen bilateral efforts to fight drug cartels. (STRINGER/MEXICO/REUTERS)

Mexican President Felipe Calderon apologized to the United States on Tuesday for an attack last week in which two U.S. government workers were wounded when Mexican federal police fired multiple rounds at their armored U.S. Embassy vehicle.

Speaking at a forum on Mexico’s security situation, Calderon turned to U.S. Ambassador E. Anthony Wayne and promised that the Mexican attorney general would get to the bottom of the case. Calderon also suggested that 12 federal police officers arrested Monday for alleged involvement in the shooting might have ties to criminal organizations.

Calderon’s comments coincided with new indications that the wounded U.S. officials were CIA employees. The agency link was first reported in the Mexican media. U.S. public records suggest that the name reportedly used by one of the shooting victims was a CIA cover identity associated with a post office box in Dunn Loring, Va. The agency declined to comment.

Calderon also did not address those reports Tuesday.

The CIA has expanded its presence in Mexico significantly in recent years as part of a broader U.S. effort to assist the Mexican government’s crackdown on drug cartels. Former senior CIA officials said the agency has shared intelligence with Mexico and helped its elite counter-narcotics teams root out corruption and identify officers with ties to drug lords.

But the former officials said the CIA has been frustrated by delays that can last months before Mexican authorities mount operations based on U.S.-provided intelligence and acknowledged that lingering mistrust makes the agency reluctant to share its most sensitive information even with vetted Mexican units.

Top Mexican officials have long denied or played down links between the CIA and their military.

The two U.S. employees and a Mexican navy captain serving as an interpreter were heading Friday to a navy training camp south of Mexico City when, the U.S. Embassy says, they were ambushed.

One of the wounded men was attached to the U.S. Embassy in Mexico City, and the other appeared to be in Mexico on temporary assignment, according to U.S. law enforcement officials and diplomats who spoke on the condition of anonymity because the case is under investigation.

Officials with the FBI, the Pentagon and the Drug Enforcement Administration have said that the men were not employees of their agencies. The State Department also has declined to comment on whether the men were agency employees.

But an examination of public records suggests that the name used by one of the men may be fictitious, with similarities to others created by the CIA to provide cover for its officers overseas.

Shortly after the shooting, major Mexican news organizations identified one of the U.S. officials as Stan D. Boss, a name associated with a post office box at a Dunn Loring mail facility tied to at least one previous CIA cover identity that was publicly exposed. Records indicate that Boss was issued a Social Security number in Texas in 2004. Beyond that, the records are largely blank, with not even a date of birth associated with the name.

That same Dunn Loring post office is linked to dozens of other names that have similarly scant records and to Social Security numbers issued around the same time. Among the previous holders of post office boxes at that location was an individual named Philip P. Quincannon, who apparently does not exist but who was listed as an officer with at least two aviation companies suspected of involvement in CIA rendition flights after the Sept. 11, 2001, attacks.

Within hours of the attack Friday, Mexican media were publishing two names that they said belonged to the victims. Mexican media outlets first mentioned a CIA connection to the case Tuesday morning.

The Mexican news media reported, and U.S. law enforcement officials later confirmed, that the Americans came under attack by Mexican federal police officers who were dressed in civilian clothes and driving civilian vehicles.

According to the accounts, the Americans were driving the embassy armored car when they were confronted at a checkpoint by a carload of Mexican federal police officers. The Americans, threatened by what appeared to be civilians brandishing military weapons, quickly fled the scene.

Soon after, a total of four vehicles, all civilian and all containing Mexican federal police personnel, got into a high-speed chase, shooting at the fleeing Americans, according to the accounts.

The Americans sped down a winding, potholed mountain road, past pastures and small farms. An officer in the Mexican army on patrol in the hills said the area was not a hot spot for drug cartels but was beset by small-time thugs who kidnapped victims and stole their phones and credit cards. The victims were often left tied to trees.

The Americans were eventually surrounded and the federal police fired multiple rounds at their vehicle, close enough to see who was inside, according to an account in the newspaper La Jornada.

Some Mexican law enforcement officials have said that the confrontation was caused by confusion — that the federal police were in the area chasing kidnappers who had seized the head of the National Anthropology Museum.

A spokeswoman for the museum said it had no reports indicating that anyone from the institute had been kidnapped.

Miller reported from Washington. Julie Tate in Washington and Gabriela Martinez in Mexico City contributed to this report.