Four female workers were killed and seven others injured in a head on collision between a truck and a human hauler in Bottoil area of Kushtia district.According to source, a truck collided with the human hauler carrying the workers on Kushtia-Jhenaidah highway around 7am on Monday. Two of them was died on the spot.Later, locals and fire brigade rescued the injured persons and sent them to Kushtia General Hospital where two others died under treatment.Sub Inspector of Kushtia Model Police Station Azizur Rahman confirmed the incident.