Mexico reports large-scale firefight in cartel stronghold; death toll not yet clear

Mexican state police stand guard near the entrance of Rancho del Sol, near Vista Hermosa, Mexico, Friday, May 22, 2015. About 40 people were killed Friday in what authorities described as a large-scale shootout between law enforcement and criminal suspects. Almost all the dead were suspected criminals, said a Federal Police official. The confrontation, which occurred near the border of Michoacan and Jalisco states, started when federal police officers tried to pull over a truck on the highway near the ranch. (AP Photo/Refugio Ruiz) (The Associated Press)

A Mexican Army soldier, seen through a chain-linked fence, stands guard near the entrance of Rancho del Sol, near Vista Hermosa, Mexico, Friday, May 22, 2015. About 40 people were killed Friday in what authorities described as a large-scale shootout between law enforcement and criminal suspects. Almost all the dead were suspected criminals, said a Federal Police official. The confrontation, which occurred near the border of Michoacan and Jalisco states, started when federal police officers tried to pull over a truck on the highway near the ranch. (AP Photo/Refugio Ruiz) (The Associated Press)

Mexican state police stand guard at the entrance of Rancho del Sol, near Vista Hermosa, Mexico, Friday, May 22, 2015. About 40 people were killed Friday in what authorities described as a large-scale shootout between law enforcement and criminal suspects. Almost all the dead were suspected criminals, said a Federal Police official. The confrontation, which occurred near the border of Michoacan and Jalisco states, started when federal police officers tried to pull over a truck on the highway near the ranch. (AP Photo/Refugio Ruiz) (The Associated Press)

Two Mexican officials say a large-scale firefight broke out Friday when federal forces came under fire in an area of western Mexico dominated by drug cartels.

One official said a convoy of federal police and soldiers were ambushed near the border of Michoacan and Jalisco states. Neither official could confirm a number of dead. A federal police official said the country's top security officials are en route to assess what happened.

The area between Michoacan and Jalisco is known as a stronghold of the Jalisco New Generation Cartel, which has mounted several large-scale attacks on federal and state forces in recent weeks.

Both sources spoke on condition of anonymity because they were not authorized to speak to the press.