Two U.S. government employees were shot and wounded in an attack on their vehicle south of Mexico City on Friday, a law enforcement official said.
The two were riding in an armored U.S. Embassy vehicle when they came under fire on a highway leading to the city of Cuernavaca.
The official, speaking on condition of anonymity, said both were hospitalized, one with a wound to the leg and the other hit in the stomach and hand.
The official said the wounded were not agents of the Drug Enforcement Agency or FBI.
The U.S. Embassy had no immediate comment.
A Mexican army official said the sport utility vehicle with diplomatic plates was found after a report about a shootout on the highway. The army official was not authorized to be quoted by name. He said a Mexican navy captain was also in the vehicle, but was not injured.
The Toyota SUV was riddled with bullets, most concentrated around the passenger-side window, indicating possible involvement by experienced gunmen.
Attacks on diplomatic personnel are extremely rare in Mexico.
In 2011, one U.S. Border Patrol agent was killed and one wounded in a drug gang shooting in northern Mexico.