WEB DESK: Three cities of Pakistan have made it to the the top 20 most polluted cities of the world.
A survey by the World Economic Forum has ranked Karachi, Peshwar and Rawalpindi in the list.
Karachi is the fifth most polluted city followed by Peshawar and Rawalpindi.
Delhi, the Indian capital tops the list of most polluted city of the world. Thirteen of the most polluted countries are in India.