Mexico's government has declared a first-ever "gender alert" for a central state due to a high incidence of killings and disappearances of women.

The alert for the State of Mexico, outside the capital, was decreed by the Interior Department. It cites "systematic violence against women" and "an atmosphere of impunity and permissiveness" toward such crimes.

The report says more than 1,700 women were slain in the state between 2005 and 2014, and at least 4,281 women and girls disappeared. Most of the missing reappeared alive, but 1,554 have never been heard from again.

The alert triggers measures designed to spur investigation and prevention, though none have officially been announced.

Maria de la Luz Estrada of the National Citizens' Observatory on Femicide said Wednesday that the alert sets a "historic" precedent.