The National Green Tribunal-appointed Yamuna Monitoring Panel has asked the Delhi Pollution Control Committee to find the reason for foaming Yamuna river and submit a report, days after pictures of Chhath Puja devotees standing knee-deep in froth-spewing Yamuna emerged.

In a letter to DPCC, the monitoring panel said the shocking pictures have got extensive media coverage and have gone viral on Twitter with “very damaging comments” on the toxicity in the river.

“The exact location is not clear and obviously, if it is in Delhi, the enforcement action by the Commissioner (Industries) and the DPCC has been lax,” it said.

The panel asked the pollution control committee to identify the location, the reason for such discharge into the river and submit a report. “From the picture, it does appear to be around confirming or non-conforming industrial areas… Necessary action to close down industries that are creating such environmental hazards needs to be taken,” the committee directed.

The pictures showed women standing knee-deep in foaming, polluted Yamuna as they offered prayers to the rising sun on Chhath Puja on Sunday. The devotees, however, did not get a full view of the sun due to thick smog.

New Delhi has been enveloped in heavy, toxic smog since Diwali which touched the worst levels in recent years, many flights were diverted or delayed as politicians blamed each other for failing to tackle the crisis. Every winter, the megacity of 20 million people is blanketed by a poisonous smog of car fumes, industrial emissions and smoke from stubble burning at farms in neighbouring states. The national capital is following the odd-even scheme started by the Aam Aadmi Party which will continue till November 14.