ARIFWALA- A woman and two school-going brothers died in two road accidents occurred in different areas due to dense fog here on Friday.  According to rescue sources, the accident occurred when a bus hit a motorcycle in Arifwala on Pakpattan Road, leaving two brothers going to school dead on the spot.  In another accident which occurred in Zafarwal, a tractor-trolley collided with a motorcycle due to dense fog resulting in the death of a woman while two children and driver sustained injuries. The flow of traffic was adversely affected by severe fog on roads. The Motorway Police have advised citizens to avoid unnecessary driving.  Dense fog engulfed different cities of Punjab, increasing severity of the coldness, especially in the morning.