Delhi woke up to a thick blanket of smog amid warnings by weather officials of falling air quality.(File)

The Congress today said New Delhi is facing a "pollution emergency" and Prime Minister Narendra Modi has kept silent on the issue.

Congress spokesperson Abhishek Manu Singhvi also targeted Delhi Chief Minister Arvind Kejriwal on the issue, saying there is a mutual blame game in which people of the national capital are suffering.

Mr Singhvi said PM Modi keeps talking of "Swachch Bharat" but the air quality of Delhi and several other cities is going down.

"What is the point of talking of Swachch Bharat when the most important aspect should be tackling pollution. How can the Prime Minister be quiet? There is an emergency as far as pollution is concerned. Delhi is the world's most polluted mega city," he added.

Mr Singhvi said Delhi had been ranked "greenest capital of the world" when Sheila Dikshit was the Chief Minister.

Delhi and its neighbouring region today experienced the first smog of the season with air pollutants many folds higher than the permissible limit. The air quality was in the "severe-plus" or "emergency" category.