Islamabad, Sept 10: A passenger bus travelling along a mountain road in northwestern Pakistan went out of control and fell into a ravine, killing six people and injuring 40 others, police said today. Three of the injured were in serious condition after the crash yesterday near Havelian, about 40 km northwest of the capital Islamabad, said Mohammed Firdous, a police official in Havelian. Speeding was the likely cause of the accident, according to Firdous. He said police were investigating. The total number of people in the bus was not known. Public transport buses in Pakistan are often overcrowded. Bureau Report