Gunmen have stormed a rehabilitation centre in a Mexican city, shooting dead 19 people and wounding at least four others, police say.
The killings happened in the northern city of Chihuahua, about 210 miles (350km) south of Ciudad Juarez and the border with El Paso, Texas.
One report said up to 30 gunmen were involved in the attack.
Several other people were wounded in the assault, although the exact number is not yet known.
Chihuahua state police spokesman Fidel Banuelos said the attackers had left messages accusing the victims of being criminals.
The attack took place on Thursday night, but has only just been reported.

The killings happened in the northern city of Chihuahua, about 210 miles (350km) south of Ciudad Juarez and the border with El Paso, Texas.
One report said up to 30 gunmen were involved in the attack.
Several other people were wounded in the assault, although the exact number is not yet known.
Chihuahua state police spokesman Fidel Banuelos said the attackers had left messages accusing the victims of being criminals.
The attack took place on Thursday night, but has only just been reported.