Two US Embassy employees were shot at and wounded by Mexican police after they were caught up in a police chase on the outskirts of the capital.

Police fired on the vehicle in which the embassy employees were travelling, which carried diplomatic plates, after the driver veered out of the way when he saw the officers' weapons.

The two injured employees were taken to a hospital for treatment and their injuries were not life-threatening.

The US government said the two employees were in a stable condition.

The US Embassy in Mexico said in a statement that the diplomatic vehicle was "ambushed by a group of individuals" and "sustained heavy damage" as a result of the attack.

A Mexican government security official said federal police had thought the vehicle belonged to a group of suspected kidnappers they were pursuing, and opened fire on it.

The incident took place on a highway on the southern outskirts of Mexico City close to the city of Cuernavaca, which has been ravaged by criminal gangs during the government's conflict with drug cartels.

The US Embassy said it has been "cooperating closely" with the investigation initiated by Mexican authorities.

Roadside shootings have been a feature of the violence linked to drug gangs that has overshadowed President Felipe Calderon's six years in office.

Gangs have been known to set up fake military checkpoints to ambush rival groups.

Last year, two US Immigration and Customs Enforcement agents were shot on a major Mexican highway. One of the agents died.