Mexican police are investigating the murder of three people with ties to the U.S. consulate in Mexico's northern city of Ciudad Juarez, an official said Monday, Xinhua reported.
Carlos Gonzalez, spokesman for the General Prosecutor's Office of Chihuahua state, told a local radio station that preliminary investigation showed the alleged killers were from the gang "the Aztecas" linked to the Juarez drug cartel.
An employee of the U.S. consulate in Mexico, along with her husband, and the husband of a Mexican consular employee, were shot to death on Saturday.
Gonzalez said agents from the U.S. Federal Bureau of Investigation (FBI)and the U.S. Drug Enforcement Agency would work with the Mexican authorities to hunt for the murderers.
Eduardo Esparza, another spokesman for the office, said many FBI agents were already in Ciudad Juarez to join the investigation.
"The FBI will evaluate the situation and establish some security strategies to solve the killing," Esparza said.
U.S. President Barack Obama said he was "deeply saddened and outraged" over the murder, White House spokesman Mike Hammer said earlier in a statement.
In light of the situation in Mexico, the U.S. State Department on Sunday issued a travel warning to American citizens traveling to and living in Mexico, informing them of the security situation in the country.
The State Department has also authorized the departure of dependents of U.S. government personnel from U.S. consulates in the six northern Mexican border cities of Tijuana, Nogales, Ciudad Juarez, Nuevo Laredo, Monterrey and Matamoros until April 12.
President Felipe Calderon will visit Ciudad Juarez soon to supervise the progress of security that he promised after 15 youngsters were shot dead at a party in the city on Jan. 30.
Meanwhile, the Mexican authorities found five bodies on Monday on the side of a highway that leads to Parral town, 220 km south to Ciudad Juarez.
The bodies, found under a van, bore signs of torture and multiple gunshot wounds. The victims have not been identified. Police also found more than 50 bullets of different calibers.
Ciudad Juarez, a city of 1.5 million on the border between Mexico and the United States, holds Mexico's record in bloodshed.
Last year alone, more than 2,600 people were killed there in drug-related gang crimes in the city.
During the last three years, organized crime has caused more than 17,000 deaths in Mexico, according to local media counts.