A thick layer of toxic smog engulfed parts of the national capital on Wednesday, with visuals emerging from the ITO area amid worsening air quality. The Commission for Air Quality Management (CAQM) has invoked all actions under GRAP Stage-IV in Delhi-NCR. (Pics/PTI)

A thick layer of fog stretching from Punjab to Bihar reduced visibility across the Indo-Gangetic plains on Friday morning, with the India Meteorological Department (IMD) issuing a red alert for Delhi and warning that road, rail and air traffic may be affected. (Pics/PTI)