Cold conditions intensified in parts of north India on Saturday, with many parts blanketed by thick fog that led to several vehicle collisions, leaving four dead and about 30 injured. The mercury in the Kashmir Valley, which has been experiencing sub-zero temperatures for some days now, dipped further and Delhi recorded the coldest morning of the ongoing winter season. It was biting cold in many parts of Punjab, with the temperature dipping to a bone-chilling 1.1 degrees Celsius in Hoshiarpur, the India Meteorological Department said. Fog reduced visibility in the morning in some other places in Punjab and neighbouring Haryana. A car and bus collided on the Hoshiarpur-Dasuya road here Saturday morning, killing four men and injuring one person. The accident occurred due to poor visibility caused by dense fog, the police said. Amritsar recorded a low of 1.3 degrees Celsius, Bathinda 3.4 degrees Celsius, Faridkot 3.2 degrees Celsius, Patiala 4.4 degrees Celsius and Gurdaspur 3.2 degr