Gunmen killed two foreigners as they arrived at a private residence in the Pradera Dorada district of Culiacan, the capital of the northwestern Mexican state of Sinaloa, officials said Wednesday.
The victims, identified only as American John Mawer "N," no age, and Colombian Alexis "N," no age, were murdered on Tuesday night, the Sinaloa Public Safety Secretariat said.
The two men were ambushed as they got out of a late-model blue BMW by several gunmen.
The assailants fled after the shooting and their whereabouts is unknown, the secretariat said.
Officers from several law enforcement agencies, paramedics and Sinaloa Attorney General's Office personnel responded to the shooting and gathered evidence at the crime scene.
Sinaloa is home to the powerful drug cartel that bears the state's name.
The Sinaloa organization, sometimes referred to by Mexican officials as the Pacific cartel, is the oldest drug cartel in Mexico and has large smuggling and distribution networks in South America, the United States and Europe.
The cartel's leader, Joaquin "El Chapo" (Shorty) Guzman, is awaiting trial in New York on drug trafficking and other charges.