Mumbai: Three police officers, who had disguised themselves as passengers and travelled in a bus to nab dacoits looting motorists on the Mumbai-Ahmedabad national highway, sustained injuries after they were allegedly attacked by the dacoits in the wee hours. Constables laid a trap for the dacoits who had carried out a series of thefts on the highway at Ambivli. Two dacoits have been remanded to police custody.