New Delhi shuts primary schools as smog persists in Indian capital

Residents in India's capital New Delhi wake under a blanket of choking smog on Friday, a day after authorities closed primary schools and imposed measures aimed at alleviating the annual crisis.

Delhi's air quality nonetheless deteriorated to "hazardous" levels for the fourth consecutive day this week, according to monitoring firm IQAir. Delhi and the surrounding metropolitan area, home to more than 30 million people, consistently tops world rankings for air pollution in winter. The smog is blamed for thousands of premature deaths each year and is an annual source of misery for residents.