The incident occurred when JMM leader Sukhdeo Hembram's went to drop his 25-year-old son Laxman at a bus stand near Chakradharpur station and noticed Ratan Tiu, a criminal, sitting in a bus, police superintendent Sudhir Jha said.
Sukhdeo immediately called his bodyguard and tried to catch the criminal, Jha said. Following a scuffle between the man and the bodyguard, Tiu snatched his service revolver and fired at his son who suffered bullet injury.
Laxman was immediately rushed to the railway hospital at Chakradharpur where he succumbed to his injuries, the police said. A police team, which rushed to the spot, arrested Tiu. Jha said the incident did not have political links.
Meanwhile, JMM supporters in large numbers assembled in front of the hospital and protested the killing. They were also forcing shop owners to down their shutters.
Naxals had gunned down JMM MP and party general secretary Sunil Mahato, two of his body guards and a party colleague during a football match to mark Holi festival at Bakuria, 40 km from Jamshedpur, on Sunday.