A Mexican official said about 40 people were killed in large-scale firefight between law enforcement and criminal suspects in western Mexico.
The official said almost all the dead were suspected criminals. He spoke on condition of anonymity because he was not authorized to speak to the news media.
The gun battle happened in area between Michoacan and Jalisco states that is known as a stronghold of the Jalisco New Generation drug cartel, which has mounted several large-scale attacks on federal and state forces in recent weeks.
The scene of the shootout is close to the community of La Barca, where authorities earlier found more than five dozen bodies in mass graves linked to the Jalisco New Generation cartel. The area also has been marked by killings of politicians.
While there was no immediate confirmation that the Jalisco cartel was involved in Friday's shooting, the gang has been involved in the deadliest attacks against law enforcement in recent memory in the last few months.
In April, gunmen believed linked to the cartel ambushed a police convoy in the western state of Jalisco, killing 15 state police officers and wounding five.