India, July 11 -- Americans in parts of Arizona and Colorado are being urged to stay indoors as blowing dust and wildfire smoke combine to create hazardous breathing conditions.

Emergency air quality advisories have been issued in Arizona and Colorado, with hazardous breathing conditions expected to last through Saturday.

Authorities are advising residents to limit time outdoors, avoid strenuous physical activity and keep windows closed where possible until conditions improve.

The advisories remain in effect through Friday evening in parts of Arizona and until Saturday morning in portions of Colorado.

The warnings are especially urgent for older adults, young children and anyone with asthma, heart disease or other respiratory conditio...