Two more police officers have been arrested in connection with the attack in August on a U.S. Embassy vehicle, bringing to 14 the number of law enforcement agents detained in the course of the investigation, Mexican Attorney General Marisela Morales said.

Twelve officers were initially arrested and placed in preventative detention, with two more now detained because they were present when the incident occurred and can provide statements to investigators, Morales said in a press conference Saturday.

On Aug. 24, two U.S. Embassy officials - both security experts - and a Mexican marine were shot and wounded by Federal Police officers while traveling in an armored SUV with diplomatic plates on a road in the central state of Morelos.

The officers involved in the shooting were investigating the kidnapping of a federal official, the Public Safety Secretariat said earlier this month.

The U.S. Embassy in Mexico City initially described the incident as an "ambush."

A judge initially ordered the 12 officers held under "arraigo," a controversial instrument under which Mexican authorities can hold people linked to serious crimes for up to 80 days without formal charges, for 40 days while they are investigated for alleged "abuse of authority" and other crimes.

The results of the investigation will be released before the 40-day period expires, the AG said.

"The investigation is very advanced and in the short-term we will be able to release the results. It has been arduous work and the conclusions will clarify what happened," Morales said.

Investigators are looking at the possibility that the deatained officers may have had links to organized crime groups, Morales said. EFE