Dense Fog Envelopes North India, Delhi As Winter Sets In — IN PICS

BSF troops wading through a thick blanket of fog and patrolling the India-Pakistan border. (Source: ANI)

As visibility dropped below 10 meters, the troops alertness increased. (Source: ANI)

During zero visibility, induced by dense fog, the BSF personnel is seen whistling. (Source: ANI)

Buddhist monks walk through a thick blanket of fog in Varanasi, Uttar Pradesh. (Source: ANI)

A person cycles amid dense fog on Wednesday morning in Varanasi, Uttar Pradesh. (Source: ANI)

People stand in front of a bonfire to warn themselves as temperature drops in Varanasi, Uttar Pradesh. (Source: ANI)

Children are seen riding cycles to their school during a cold and foggy morning in New Delhi. (Source: PTI)

Vehicles drive by amid dense fog in Delhi on Wednesday. (Source: ANI)

People do yoga at park during a cold and foggy morning in New Delhi on Wednesday. (Source: PTI)