A thick layer of smog - a toxic blend of smoke and fog - enveloped the Delhi-National Capital Region (NCR) this morning as the air quality index (AQI) plummeted to the "severe-plus" category, forcing authorities to announce stricter pollution control measures.
Smog also affected visibility in the national capital, which hit flight operations and train services. Visibility at Palam dropped to 150 metres at 5 am.
