India has launched a program to rein in dangerous pollution levels in more than a hundred cities, an initiative the government expects to significantly improve air quality.

But the plan drew immediate criticism from environmentalists, who said it lacked a clear framework to tackle toxicity levels that have led to millions of deaths.

India is home to the world's 14 most polluted cities, according to the World Health Organization. Toxic air claimed 1.24 million lives there in 2017, a study in Lancet Planetary Health showed last month.