Cartels Tijuana fires
Relatives of a woman who died in a fire at a convenience store that was burned by unknown attackers, in a simultaneous attack of fires in different parts of Ciudad Juarez, according to local media, react outside the store on Aug. 11. REUTERS/Jose Luis Gonzalez

Hundreds of Mexican soldiers were sent to Ciudad Juarez Friday while violence sparked in the border town near Texas may be linked to a series of incidents in Tijuana and the surrounding area.

The situation began in Ciudad Juarez with a prison face-off between members of two rival cartels, which caused a riot and shootouts that left 11 people dead, most of them civilians, authorities said.

The violence then apparently moved west. The U.S. Consulate in Tijuana warned American citizens late Friday to avoid the area, while acknowledging that officials are “aware of reports of multiple vehicle fires, roadblocks, and heavy police activity in Tijuana, Mexicali, Rosarito, Ensenada and Tecate.

The Twitter post noted that U.S. government employees have been instructed to shelter in place until further notice. Officials had issued a travel alert last month.

According to one account, 19 fires had been reported throughout Baja California. Broadcast media showed images of multiple vehicles, including vans and delivery trucks, ablaze.

Tijuana’s mayor Montserrat Caballero urged cartels to leave innocents alone, while various police agencies and other government organizations posted warnings or closure notices to social media.

Another official, Baja governor Marina del Pilar, condemned the violence on Twitter, and urged residents to remain calm. She said “there are already detainees” being held who are believed “responsible for the events.”

The violence began Thursday in Ciudad Juarez, just over the border from El Paso. Los Chapos, members of the infamous Sinaloa Cartel formerly led by Joaquin “El Chapo” Guzman, and local group Los Mexicles clashed in a prison in the afternoon, Deputy Security Minister Ricardo Mejia said.

A riot then broke out, in which two people were shot to death and four left with bullet wounds, Mejia said, speaking alongside Mexican President Andres Manuel Lopez Obrador at a regular news conference.

Another 16 were injured in the fighting, he said. Officials did not say what caused the clash.

But the rampage spread outside the prison to the city due to the Mexicles, authorities said, and nine civilians died including four employees of a radio station, among them one announcer.

Across town, convenience stores were shot at and set on fire. FEMSA, the parent company of the Oxxo chain, said in a statement that one of its employees and a woman who was applying for a job died in the violence.

Around 1 a.m. Friday morning, six alleged members of Mexicles were arrested by local police, with help from the Army and National Guard, Mejia said.

By Friday afternoon, some 300 Army soldiers were scheduled to arrive in town, with another 300 to follow.

“(Juarez) Mayor Cruz Perez has let us know that (the city) is now in a state of calm; public order has been re-established,” Mejia said.

“We hope it doesn’t happen again, because innocent people were attacked,” the president said.

Thursday’s attacks follow clashes between cartels and the military in central Mexico, which led to taxis, buses and some 20 Oxxo stores being set ablaze, Lopez Obrador said.

“We should not and cannot get used to this type of event,” said retail group ANTAD. “Mexico does not deserve it.”

(Reporting by Kylie Madry, with additional reporting by Tomas Bravo; editing by Ros Russell and Alex Richardson)

Reuters and staff reports