New Delhi: The coal mafia was behind the brutal attack on SAIL Chairman Anil Kumar Chaudhary on August 7. A deep rooted conspiracy was hatched by a Delhi-based coal industrialist who hired assailants to eliminate Chaudhary, who had rejected a contract worth over Rs 100 crore. Six persons, including A.K. Singh, owner of a coal firm, has been arrested by the Crime Branch of Delhi Police in connection with the case. The coal industrialist had paid Rs 6 lakh to hire criminals to allegedly kill Chaudhary. Chaudhary was attacked by four assailants on August 7 in South Extension near his office in the posh HUDCO place in South Delhi. The assailants had trailed the SAIL Chairman’s car from his office and after overtaking his vehicle at a secluded spot, they hit him with blunt objects, leaving him severely injured. Chaudhary later said that the assailants had a clear cut intention to kill him.