Heavy rush of passengers traveling to Bihar and parts of Uttar Pradesh was seen at the New Delhi Railway station due to the Chhath Puja.

Two-thirds of the world's population will be living in cities by 2050, the United Nations has projected, with India, China and Nigeria set to drive a surge in urbanization.

Today, around 55 percent of the world's population is thought to be living in an urban area or city, with that figure set to rise to 68 percent over the coming decades, according to the "Population Division" report from the UN's Department of Economic and Social Affairs.

The study, published Wednesday, also forecast a dramatic upswing in the number of megacities around the world. To date, there are 33 urban centers with populations of more than 10 million people — although this is expected to rise to 43 by 2030, mostly in developing countries.

In 1990, there were just 10 megacities worldwide.