Two disabled police officers, part of a special unit to help the disabled, were shot dead while on traffic patrol in northern Mexico, an official said Saturday.
Unknown assailants opened fire on the men from a car at an intersection in the northern city of Chihuahua on Friday, said state Public Safety spokesman Carlos Rodriguez.
Tirso Reza, 50, and Jose Luis Paez, 47, worked for a police unit dedicated to helping disabled people, including by ensuring that parking spaces designated for them were not illegally occupied. Reza was wheelchair-bound, while Paez had extremely weak eyesight.
Investigators did not know why they had been targeted, Rodriguez said.
Mexico is suffering a brutal crime wave as drug gangs step up attacks against rival groups and police. Soldiers and federal police have been waging an offensive against cartels for two years, but decapitated bodies regularly turn up in public.
On Saturday, a judge ruled that three men detained in a September grenade attack will stay in jail pending trial, according to the Attorney General. The men allegedly threw grenades that killed eight revelers at an Independence Day celebration in the city of Morelia.
Prosecutors say Julio Cesar Mondragon, Juan Carlos Castro and Alfredo Rosas belong to a group of Gulf Cartel hit men known as "Zetas." In a video distributed by prosecutors days after the Sept. 15 attack, Castro tells an investigator their aim was "to frighten and provoke the government."
But the defendants' wives said their husbands had been in the port city of Lazaro Cardenas, 250 miles south of Morelia, on the day of the attacks. They said the men had been kidnapped and tortured into confessing by unknown gunmen who turned them over to authorities.