The violent drug war in Mexico is escalating following an attack, Saturday, in Ciudad Juarez that killed 16 people.

Four police officers died when their car was ambushed. Stray bullets also hit two bystanders -- one a 10-year-old girl.

A day later, armed commandos attacked two drug rehabilitation centers in the city, leaving four dead and five wounded.

Gangs have attacked dozens of drug rehab clinics across Mexico, including nine last summer.

Drug cartel leaders sometimes operate the centers themselves in order to recruit addicts -- subjecting the clinics to attacks from rival gangs.

Ciudad Jurazez is just across the border from El Paso, Texas.

Two drug cartels there are battling for control, and it's now considered one of the most violent cities in the world.