Kolkata: At least 20 people have been injured after a bus collided head on with a truck coming from the opposite direction.The incident took place at Suri in Birbhum on early Monday morning. The incident triggered tension among the locals, some of whom took part in the rescue operation.The injured victims were all taken to the district hospital in Suri. According to the hospital sources, some of the passengers are stated to be in a serious condition. Also Read – Rain batters Kolkata, cripples normal lifePolice said the accident took place near Suri bus depot. A state government-owned bus of South Bengal State Transport Corporation started its journey from the Suri bus terminus at around 4.30 am. The Salt Lake Karunamoyee bound bus was carrying around 35 passengers when the accident occurred.After locals initiated the rescue operation, police reached the spot. They took the injured passengers to the hospital. Frontal portion of both the vehicles have been damaged in the accident. The circumstantial evidence suggests that both the vehicles were running at a high speed when they collided head on.Locals heard a loud thud and rushed to the spot and passengers were shouting for help.Police suspect that the truck driver lost control over the vehicle and this resulted in the accident. The drivers of both the vehicles escaped unhurt.Police are investigating if any of the drivers had fallen asleep at the time of the incident.