Two brothers were hacked to death by an unidentified gang that beheaded them and threw their severed heads on the road near the Medical College in Chidambaram town of Cuddalore district in Tamil Nadu, the police said. The gang attacked the ambulance in which Kumar and his brother Rajesh were travelling using country bombs and sickles around mid-night last night.  Their severed heads were found on the road near the medical college, close to the site where they were attacked, the police said.